I bought one of the 72" Extras about a year ago - just getting around to putting it together now. It seems that GSP doesn't have anymore of them - not sure if Chief does or not. I liked the looks of the Extra better, but the Katana seems to be more popular.
Do what you can to keep these planes light - they will definitely fly better. The wing loading numbers look high, but they really aren't. The CMP planes seem to calculate wing area differently sometimes - they sometimes (but not always) figure only the wing panels. Most other planes go by the total wingspan and average cord - which makes the wing loading numbers much lower.
The landing gear on both of these planes is an anchor. You can save 5 oz right off by replacing with a CF gear from Fiber-Lite.

You can't beat the price of these things. Even if they aren't the best flying planes in the world (although reportedly they ARE pretty good), you will be more inclined to fly 'em hard and try stuff you wouldn't with a plane that costs 3X as much. That's the main reason I bought mine - I figure if I stuff it, for another $200 and a few hours I can be flying again with a new one. I wouldn't spend many hours trying to patch up a damaged plane that is this cheap