Duratrx is known for taking other manufacturers platforms and changing them slightly, not unlike oh, everyone else in todays market. Sometimes they do it right, sometimes they do it wrong.
Seriously though, just how different can something be, and when you look through all the threads, can anyone name one rig that doesn't need upgrades to bring it up to scratch. When I buy cars, I look at chassis strength, tranny and diffs.
Most people change engines anyway, they break arms and shocktowers, and just generally turn it into an aftermarket brand.
I actually have an HSP Atomic Warhead buggy. Its an .18 with a 2 speed. It flies. I crashed it after about two hours, destroyed the entire front end, and replaced it for about $45 off ebay.
Having raved on for an hour my high end gear is by far the best, and most of its relatively stock, but I dont catch 30' air either.
Take a look at R/C Car test on the RTX 27. August edition