I use les paul standards(w/EMGs), monster cables, a few pedals, and 2 amps(AB box). The Q20 is in the loop of my lead amp (a soldano-type gain modded 100wt tube head)...a roctron hush IIC is after it, I think the head is noisy-not the Q20. My cabs are various 2x12s and 4x12s w/65wt & 85wt celestions. I'm after the Zakk "Mr. Tinkertrain sound"...I have it. I love the chorus, delays, the 5 band EQ is useful (I use it very lightly). I like the reverbs, but wish they were a little darker & deeper (think of the solo for Led Zep's 'what is and what should never be'). I think the Q20 sounds a bit sterile, but the super lush chorus wins me over...I do get several comments on my "sound"...(p.s. who would use the overdrive effect? Not me)-I start my main sound starts on preset #63("guitar rack 01" is the title)
I had a Q2 that I had to get serviced once with little to no hassles, but the Q20 hasn't stopped on me yet. I have 2 amps, so I don't need a back-up. I don't think I would ever carry a back-up processer.
Overall, for the $$ I don't think I could do better for the $500 range (or more). I've had rocktron effects(intellifex, Chameleon) and would not go back. The Rocktrons might be a little warmer, but the Alesis sounds more lush and studio-like ( in a live setting-which is my primary usage)