I bought a power amp today. I went with the QSC 850. It cost me $299. I was comparing it against the Nady SPA 1400. They were the same price but bridged Mono @ 4 ohms the Nady had 600 watts more than the QSC. HOWEVER... Musiciansfriend.com was not able to tell me the difference between the spa and the za models of Nady, and they didn't know what the Warranty was for the Nady power amp either. So I called Nady. 1st, they had no 800 number, not even for sales calls. So I am calling long distance. 2nd, they were really bothered by the fact that I called. They asked me three to four times why couldn't I look up this info on their web site. 3rd, they didn't know the difference between the two amps. 4th, they didn't know what the warranty was. 5th, they transfered me to their ONE tech support rep, who never returned my message. ... so ... I bought QSC.