Rumor has it that the Mackie power amps are not durable.  I don't have this first hand, but it's what I've heard.
 
Bradley

My Mackie 808s P.A. has dual 600 watt power amps.  I love it.  It's never given me any trouble.
 
Bill, tgo

I've used a Mackie M1400i for over 3 years now, both in my Bass rig and PA application, moved it once or twice a week, and never had a problem. I'm quite happy with it.  
 
Mike.......