And the 975 has an AM/FM tuner built in so the only thing the 2150 is getting you is 2-channel amplification and phono input. Both important but both can be had separately too. (oh, and USB input)

Not that I'm bad mouthing the 2150. I have both a 975 and a 2150 but as two separate setups doing different things, both very well I might add.