I have always liked QSC RMX series amplifiers for PA. Well defined and detailed sound and extremely well made. QSC are also extremely helpful with circuit details, advice and help.
Some common faults
Premature transformer failure. Very expensive replacement part at over £100 from UK distributors but thouroughly worth it once restored, these amps retail new for about £500 so repair is still very much a cost effective option.
I have also found that the fans get a little noisy over time. Given that the cooling only occurs back to front it is vital that these are kept clean and in good condition.