IME, Trace amps have a unique, identifiable tone. If you're thinking about acquiring one, you really need to try one out to see if you like the colour.
My first proper amp was a BLX80 combo. Only 80 watts but was very efficiently designed and produced volume and depth of tone that belied it's diminutive dimensions. It's preamp had a couple of neat features, two preshapes (one scooped 'rock' setting, and another more airy 'Classic Trace Elliot' shape). It also had a eq balance control that boosted bass and reduced treble one way, or vice versa the other way - this is a really easy way to quickly adjust tonal balance to suit room acoustics.
At the time I never quite got to grips with the graphic eq, but now, years after I sold the amp, it makes sense. Rather than using it for tone shaping, it's a efficient way to quickly hone in on problem room acoustic issues.
So basically, the amp had it's own voice which you could tweak to suit the room, but not really a transparent amp that you could change the colour of at the flick of a switch. But if you don't like the initial voice, then look elsewhere, as it's tricky to make it sound like anything else.