I have the Blade 400 also with Hitec 65mg servos and I am running a gy401 now as the stock one crapped out. For the $400 price you get a decent heli, charger, battery, and great tx. If you plan on the future getting the dx7 and a T rex anyway, just go that route to start with. Why waste the money on a learning copter. The parts are actually the same or cheaper for the trex. I run align blades, feathering shaft, and bearings because they are cheaper then the stock blade 400 parts.
Don't get me wrong I fly the piss out of the 400 and it works wonderful. I have flown a trex too and it just felt a little better dialed in wise. Like driving a Civic Si or an Infinity G35. Both do similar things quiet well, one is just a bit more refined.