IMO Emotiva is no doubt best bang for the buck. No question from me.
But there are various reasons for choosing different amps.
For example, the ATI amps (AT2000s & AT3000s) are fully balanced from input to output, while Emotiva amps (except the XPA1) are not fully balanced.
http://classicaudioparts.com/store/ATI-2000-Series-Amplifiers.html
Practically all amps have fuses. The ATI amps are "fuse-less". They have something like a circuit breaker. In case of overload/protection, you just have to "reset" the breaker, instead of replacing a blown fuse like most amps.
ATI, who also owns Theta Digital, has been making amps for "over half a dozen" companies like Lexicon, JBL, Mark Levinson, Earthquake, Outlaw, etc.
ATI amps are made in California, USA.
Emotiva amps are made in China.
But as PENG, others, and you already, all these amps will work just fine as long as the power output fits your requirement.
To me personally, Emotiva amps are value/budget amps with very good build-quality and performance/measurements that sound great.
If you want higher prestige, fit and finish, build quality, etc., you may want to look into Parasound, Anthem, Rotel, ATI, Sunfire.
Of course, we are not talking about higher-end and more prestigeous amps like Bryston, Krell, Mark Levinson, and McIntosh.