I can't pay the price of the 7700, but could get the 7125. Since there are some 770 on eBay, is there anything better about the 7125?
Or to ask it another way, is it better to get a 7125 (new) or 700 (used good condition) if the price is about the same?

Well, the 7125 matches the look of the 990 and 970, if you have one of those and that matters. On the other hand, the 770's warranty is transferrable, so going used isn't really a risk.

Yeah, the 7125 matches the 990, while the 770/755 matches the 950. That's no big deal sice it would be in my ent cabinet.
The 770 on eBay right now has 1 year warranty left.
I was just wondering if there was any improvements made on the 7125 (since it's newer) that aren't on the 770.