RE: who owns a hyper 9? Are they better than hyper 7?
Buggies that are designed for racing sometimes have to compromise strength for weight. The designers make a few assumptions. One would be that people that buy competition level equipment probably have some skill behind the wheel.
Under that assumption, you can compromise a little strength to make the buggy lighter because the guy driving shouldn't be having the nasty crashes a beginner would be having. The Losi 2.0 is another good example. They removed alot of material from the shock towers compared to the 1.0 version to shave some more weight.
So much so, that I think Truhe was running a revised front tower at the Nitro Challenge that had more beef to it because the Losi designers may have got a little overzealous on the weight reduction.
It's tough to find that perfect balance of durability and performance.