I've compared the older Outlaw 750 to the 7500 (my Model 7500 review touches on that a bit) and found the differences to be subtle. The 7125 offers less power than the 750, but it is also a more recent design - I'd expect the results of a 7125/7500 matchup to be similar, so long as the speakers being used and the listening room didn't create a need for the 7500's extra power.

As for the Emotiva question, I'm maybe not the best one to ask. I was involved in a very lengthy online debate about their first in-house processor design (the LMC-1). In my opinion, that product was abandoned without having a number of significant design flaws fixed, some of which were the result of intentional design decisions and others of which were potentially fixable firmware problems. Others (including Emotiva) would disagree with me on that, but the whole experience was a tiring one for me. I hope that their second generation of processors turns out better, because it's good to see more than one company doing what Outlaw has done. Much of the cost difference you will see in Outlaw vs Emotiva amps is due to the way both companies build their amps. Outlaw has been partnered with ATI for about a decade now (the Model 750 was released in 1999, I believe) for all of their multichannel amps, and ATI is a California-based outfit for both design and manufacturing. If you want a fun chuckle, check out the Secrets of Home Theater review of Lexicon's $10,000 7x300W power amp - that amp is built by ATI for Lexicon, and it bears a number of striking similarities to Outlaw's $3,500 Model 7900. There's clearly some real value in Outlaw's power amps. However, US-made power amps will invariably cost more than the Chinese-built amps that Emotiva is offering.