I have been using this power amp for over a year now to power the mains in my PA system. I have it powering 2 Yamaha BR15M 15" speakers. I actually picked it up used from a local music shop. That being said I feel that I got a great deal on it. I think when all was said and done I ended up paying around $250 for it, about half the list price. I've never had any problems with this amp, and the distortation elimination features that it has are great. I would have definitely been willing to pay full price for the amp had I bought it new, considering I got it at about 1/2 the price I feel that I got a steal!
I've used this amp in a variety of situations from small coffee shop gigs (I play acoustic guitar) to shows with over 300 or so in attendance and I've never had problems. In fact I've never had the power on each channel turned up more than 1/2 way. So needless to say this amp has plenty of power. I could probably play shows double the size of the ones I have been with no problems.
It has plenty of options and connections so there shouldn't be any problem intergrating this amp into your current PA if you are looking at add another. For example it has banana plug or speakon outs for the mains which is nice. I has 1/4" or XLR ins from the mixer which is also nice, so you have a lot of flexibility when using this amp with existing equipment or if you were to purchase new stuff.
I'm really happy with my purchase of this amp, it's the only piece of equipment that I've purchased used and I have absolutely no regrets.
I would definitely recommend this amp to anyone, great power, great flexibility, and a great price...what more could you ask for right?