i have both a 400 and trex and don't take nothing from either.i enjoy flying both and can tell the difference between the two trex is much more stable but also over 2 oz's heavier.only mod i had to do to the 400 so far was 1 turn on the rudder linkage and bound to the dx7.and that alone was a chore.for some reason the swash mixing was different between the dx6i and the dx7 trex is still in the setup stage and have had for close to a year now.it will fly and seems to fly well but no way would i try to take inverted becouse i can't get the pitch right in st1 mode.and the gy401 gyro set up confuses me so i just keep it slow and low for now till i can get set up right.i think that horrizon has put out 1 fine product this time.i liked the cx2 but hated the cpp.e-flight does need to put out a fixed pitchlike the honybee for help with the transition from coaxil to single becouse it is a pretty big step from coaxil to colective pitch.got to say that i have had the 400 since dec24th and still all in 1 piece with no troubles at all not even a blade .i say if you are new like me to helis and ready for a colective pitch heli the 400 can't be beat!RTF literaly not saying it is setup perfect but it is flyable out of the box and parts are reasonable always a plus.if you have some extra cash and want to build a real nice heli buy a trex,if you just want a nice heli ready to fly buy the b400 either way don't think you'll go wrong