The top reason to decide on a light weight RV is towability. If you're looking for something that will be easier to navigate the roads with, a light weight RV is definitely your best choice. You'll find that many light weight trailers come with options of folding or collapsing, to make towing even easier, and some also have caps on the front that can help with wind resistance on the highway.
Light weight trailers can be pulled by most cars, so you don't have to have a pickup truck to hit the road with one of these. They'll also let you get better fuel mileage than a larger, heavier towable RV ¿ a difference you'll see at the pump.
Light weight trailers also give you the freedom to come and go from your campsite as you please. You don't have to be tied to one spot the way you often are with a larger RV. Set up camp (which is also a lot easier to do in a smaller, light weight trailer), unhitch your trailer, and head into town for a gourmet dinner or to see a show without worrying about finding a large enough parking space or a place to turn around. The comforts of home will be waiting for you when you return.
Your choice of a light weight trailer will also save you money. Compared to the large quantities you have to spend to get a Class A motorhome or fifth wheel trailer with all the luxury amenities, if you don't mind roughing it a bit more, you can find light weight trailers for a much lower price, freeing you up for additional trips in the years to come!