the blade and the radsails are totally different kites in my opinion... The lift on a 4.9 blade IV is much higher than on a radsails 5. The quality of radsails is OK but the blades are better overal, sewing etc... ESPECIALLY THE BRIDALS... If you buy a blade, or any ozone, you know you're set for years. When you buy a radsails, its going to last a few years, and then you'll have to replace it or replace the bridal... you pay for what you get, a good cheap kite, and the blade is a top range model