I use it for several styles, mainly rock (AOR). It is a nice unit.
Sometimes I played live without amp (using simulated output) - sounded OK, so works well as a backup unit too.
Factory installed ECC83-CZ tube (Ruby) OK for general use, but I recommend to change tube to find your sound. I liked Electro-Harmonix 12AX7EH tube in this unit, also some NOS tubes. I do not recommend very high gain tubes (eg, Marshall), because this unit has enough gain by default.
Channel 1 should be clean, but it gets distorted easily with humbuckers, especially EMGs. With full gain and right tube it reminds me Santana. However, in this case you might have problems with volume balance between channels. If you want it really clean then you should find another 12AX7 tube for this unit.
Channel 2 is a trebly sounding channel from 80s. With max. gain you can reach sounds like Dokken or Hungarian band Pokolgep :) It works well for soft rock, but I miss sustain.
Channel 3 has a Marshall-like distortion with contour. Quite different from Channel 2, good for rhythm, heavier metal styles. With a Vox combo amp and extreme eq settings I could reproduce classic Metallica sound.
Unit is not noisy, you can connect it to effect loop of another unit, it will be usable.
Common eq is always a compromise, but I could find a way to use it for each channel.
In general I turned the bass down (unit is very bassy) and add middle (even full) depending on style.
Built like a tank :)
I felt one footswitch is easier to push than others but no problem so far.
I have used it for ages, good for various styles. I have already sold it, just to try something else.
It is really comparable to similar units, even rackmount preamps. My Engl E530 sounds very similar to this unit.
If you like its features I recommend to buy it.