I use a Fender Blues Deville (4X10) and a cheapo fender practice (solid state) amp. The BM effect is more subtle than a classic distortion pedal. Its hard to saturate the tubes on the DeVille at a manageable volume, but if you dial in a touch of tube overdrive on the amp, let the Bad Monkey introduce some nicely eq'ed, slightly overdriven boosted tone, it pushes the tubes, blends nicely with the tube saturation, and gives a sweet, harmonicaly rich overdrive, sustain, and touch sensitivity that makes playing more expressive and responsive. I can control the crunchiness with my guitar's volume control, and the tone controls on the Monkey seem to amplify the effect of tone tweaks from my axe. I don't try to emulate anyone else's sound, but I love blues with a singing tone ala Buddy Guy, early (Bluesbreakers) Clapton. I don't care for raspy, buzzy overdrive, and the BM delivers a tight yet fat signal that works will with my amp.
With the solid-state amp, it works great to boost and introduce some grit to a clean tone , (smoother, less raspy than other od/dist effects I've toyed with) but you will want something else if you are looking for a full-on rock/metal lead tone.
It does introduce a bit of noise with the gain up, but I'm crankin' when it's on, so that's not an issue for me. I have an SG with a very hot pickup (dimarzio super-distortion), which helps me avoid cranking the output on the Monkey to push my amp, and I don't want or need a super-fuzzed-out pedal for my sound or rig. (I have a RP-5 for those times). In front of the amp, the BM sounds best. In the effects loop on the DeVille, it seems to suck tone, even in bypass mode - I don't know if there is some expected impedance on the power stage input (or pre-amp output)on the amp that differs from what the BM is designed for. Not an issue when I place it between the guitar and the amp input.
The unit seems realiable like most pedals, I like the battery placement and ease of replacement. The battery life seems fine (unless you leave your axe plugged in overnight).
I play primarily blues rock, but I also play in a church band, where searing leads just don't cut it. In both situations, the BM delivers what I need. I've been playing over 15 years, had an MXR distortion +, a Big Muff Pi, a Digitech RP5, various amps, and this is the best overdrive I've used. (haven't tried them all) I tried to compare it with a Tube screamer in a store, but they had a lousy amp to demo with. I couldn't hear much of a difference, but with the tone controls, the BM sounded better to me there, so I grabbed it, and now I'm a happy monkey. (Bad too!)