Note: The Rion Prestige and Rion Green Giant are the exact same greenhouse except that the Prestige has clear side panels, and the Green Giant has opaque side panels. Other than that difference, they are the same.
Our Greenhouse Review Panel says:
The Rion Prestige / Green Giant Greenhouse was nearly our top pick, but came in slightly behind the Rion Professional because of one main reason: price. While it is also a fantastic greenhouse, it is a foot and a half taller, is outfitted with more accessories right out of the box and as such carries a bit steeper price tag. Other than that it is very comparable to the Rion Professional with the differences being height (8 feet tall instead of 6' 9"), and the clear side panels which are available in the Rion Prestige configuration. If you want the considerable benefits of the Rion Professional series, but prefer more head-room and/or clear-as-glass side panels, then the Prestige or Green Giant greenhouse is for you.

Because the Rion Prestige / Green Giant is so close in features to the Rion Professional, we will repeat some of the benefits that were written for the Professional but also apply to the Prestige / Green Giant line:

The first nice feature we discovered for the Rion Prestige / Green Giant Series Greenhouses was the wide variety of size options. You can get anything from 8'x8' up to 8'x24' or more. That means there is a size available that fits just about any requirement, from a starter greenhouse to a near-nursery sized greenhouse. The Rion Prestige / Green Giant expands in size in 4' increments, and you can purchase the 4' extension kits at any time. So if you go with an 8'x8' to start, then decide you really need an 8'x12' greenhouse, you simply purchase an extension kit and add 4' of middle space, expanding from a 8' length to 12' in length.

The next nice feature is that the greenhouse ships in several reasonably-sized packages via common carrier (Fedex or UPS typically). The exact number of packages varies depending on which size you go with. Many greenhouses ship via something called LTL Freight, which basically means a flatbed truck of some sort. When shipped via freight, the package size can be quite large, and the customer is often expected to help with unloading of the packages at the delivery site. Having the Rion Prestige / Green Giant configured to break down and ship in the smaller, easy-to-move boxes, was very nice and much better for our backs!

The frame of the Rion Prestige / Green Giant is constructed of high quality UV Protected PVC Resin, which is extremely strong, rigid, warp-proof, fade-proof, and lightweight. It has been tested for snow and wind loads, and can withstand 1100+ pounds of snow and 80mph winds, which makes it a great choice for virtually any climate, no matter how severe the weather gets.

Installation of the greenhouse is a snap - literally. The pieces are constructed to push-fit together, and don't require cutting or drilling like some of the wood-frame and aluminum-frame greenhouses on the market. Instructions are clear and well-thought out, and can be easily followed by all but the least technically minded people.

The Rion Prestige / Green Giant package includes a base kit which provides a secure foundation for the greenhouse. We found the Rion base kit to be a very secure and sure footing for the greenhouse.

Another nice feature that sets the Prestige / Green Giant apart from many competitors is the variety of accessories that are included as standard items. These include the base kit, as mentioned, plus roof windows, louver windows, automatic window openers, solar lights, rain gutters, and staging/potting tables. These standard accessories alone could cost hundreds to thousands of dollars if added to other models of greenhouses.

Conclusion: The Rion Prestige / Green Giant Series is a very close 2nd pick for us due to a number of great features which include it's method of shipment, ease of assembly, variety of sizes, height, clear-panels option, expandability, strength and durability, standard accessories, and more. It also has a reasonable price, especially when compared to models from some of the other manufacturers which can run up to several thousand dollars more for similar sized and outfitted greenhouses.

RION PRESTIGE:
Rion Prestige greenhouses offer the optimal environment for successful backyard gardening. The use of opaque polycarbonate panels on the roof sections and clear panels on all 4 sides give both protection from the sun above, and the pleasure of clear viewing from inside and out. This unique combination is both safe for your plants and offers the rich look of an all glass greenhouse.

Rion Prestige greenhouses are aesthetically pleasing and functionally versatile. The resin framework is rigid, easy to assemble using snap-fit simplicity and is visually attractive in its dark green colour and softened corners. The Dutch Darn roof design gives additional headroom unlike most other greenhouses. The all new Rion Prestige greenhouses offer a full 8 ft. of inside headroom with French doors that are a full 6 ft. 9 in. high for easy entry.

Air circulation is critical in a greenhouse and to ensure proper air circulation, the Rion Prestige greenhouses use louver windows that can be placed on the back or side panels with automatic openers that react to both hot and cold conditions. These greenhouses also include roof vents with automatic openers that react to both heat and cold. When your plants need cool air the roof vents will open automatically and will close as the growing day comes to an end.

The multi-purpose Rion Prestige greenhouses enable you to garden year-round by extending the growing season with a warm protected environment, provides an open space to bring in expensive or sensitive outdoor plants over the winter, and allows the nurturing of seedlings and annual flowers long before spring arrives. A heat source may be required for expensive or sensitive plants during colder periods.

RION GREEN GIANT:
The all new Rion Green Giant backyard hobby greenhouse features twin wall 6mm opaque polycarbonate glazing panels that create superb insulation and protection for your plants and flowers. Designed for year-round use, the Green Giant will provide you with the ideal gardening environment regardless of the season. Double doors allow for easy entry and exit and provide excellent ventilation when opened. The rich hunter green frame is thick and sturdy. The Dutch barn roof design is both elegant and functional with 8 ft. of headroom and 6'9" doors. The Green Giant is perfect for all of your gardening needs: starting seedlings, protecting valuable plants or creating a tropical garden. Our kits include a greenhouse base foundation, roof vents, 2-tier staging tables, full rain gutters with down spouts, side louver windows for cross ventilation, automatic roof vent openers, automatic louver window openers, plant hangers and a solar light so you can view and water your plants and flowers at night.

• Rich 'Hunter Green' frame color
• Overall head room height: 8 feet
• Interior wall height: 6' 9", Door frame height: 6' 9"
• C-Channel Base provided for easy assembly
• Durable resin frame construction allows for snow loads up to 1100 pounds
• Clear-as-glass or opaque polycarbonate side panels on all four sides, and 4mm opaque polycarbonate panels on roof.
• Weatherproofed, UV stabilized safety glazing for roof panels
• Standard automatic roof vent openers react to both hot and cold days and nights
• Double French Doors for easy access and additional ventilation if needed
• Standard louvre windows that can be placed on the side or rear panels
• Rain Gutters with down spouts for rain water capture and re-use
• Door height 6' 9" and inside height at peak of 8.0" for easy move-about
• Push-fit assembly: Simply snaps together, no tools or screws needed
• Very easy to understand manual with step by step assembly instructions and pictures