Even while making allowances for new-gear-syndrome, I'm very chuffed.
Everything you read about them raves about their value as a clean to cleanish boost (very clear sound, nice EQ tweaks with the lo & hi eq knobs) but seems to say that it's an average overdrive.
I agree about the clean usage - no nasty noise, very usable level boost, and a nice clear sound with no drastic tonal shift. But imho the drive sounds (bringing the gain knob beyond 1/3) are great - the same clear and un-shifted characteristics are apparent and for me that's a bonus - it's not got that intrusiveness that a Tubescreamer has, or the apparent bass-shift that a pedal trying not to get thin has (eg BD-2). It sounded especially good when splitting the humbuckers in my Morgan - I look forward to trying the Strat with it.
I've not tried it driving an already driven amp (just ran in to a mostly clean 4w valve head)