Well, the core of the OS is the same, whether it is Samsung, Motorola or HTC. Its what the OEM's add on that makes a difference. Motorola in the past has drawn some criticism over their add-on MotoBlur but they no longer use it. IMHO, your friends have a vested interest in Qualcomm so they will dislike Motorola to some degree.
I've owned HTC phones in the past (Touch Pro, Touch Pro II and EVO) and have mixed feelings. IMHO, the Maxx has been the best phone I have owned in quite some time. For once in my life I dont have a high degree of phone envy or buyers remorse. :-)