Can't say if you'd be missing anything by using a non-moto phone but I have a 1st gen X and I really like it. Had it for about a year now and I haven't looked at other phones because this one is just so good. Not sure if Moto Connect is offered on other phones but I use it on occasion.
I actually picked up my 360 based on the performance of my X.
I can say that I haven't had any of the battery or disconnect woes that I've read about on the forums. Not sure if it has anything to do with the fact that I have a Moto phone tho...