they call back within 30 to 60 minutes if you leave them a message. they email you within a day or two, even if you use the email you listed above. what other amp company do you know does any of this? i've had nothing but great experiences with their customer service. i can call them right before a gig to ask a question and feel confident doing so b/c they call right back.
i have heard of maybe 2 or 3 cases in the years i've been on this board where a mesa broke down due to something other than a tube failure. if that's not QC, i don't know what is.
as for the footswitch popping issues, all rectifiers going back several years have had this problem. it's just built up voltages that come out as a pop when you switch the channel. the solution is to flick the switches back and forth several times while the amp is in standby or right after you turn it on to let the voltages clear through. after that, you won't hear another pop until you turn the amp off and start again.