If your still looking, ill recommend the fischer amps fa4e xb. You can order them from thomann.de and get three years warranty. :)
I had the tf10 ages ago, so this is going off very bad memory. But I feel that the amps are an upgrade over them, with better sub bass and I think less mid bass (again bad memory), less recessed mids and more natural sounding treble with great extension and energy. Tf10's treble sounded a bit too artificial for me. I don't listen to metal but listen to a bit of rock and hard rock and can say the amps do well with those genre's, enough bass impact to keep them exciting with good speed to boot. Great clarity and detail with really good separation. Not the widest in terms of soundstage but its still impressive with a good sense of realism to it (being 3d). They fit me really well and isolation is excellent. Much better than than the tf10's.
Some negatives I would say the upper mids and lower treble are a bit recessed which makes the sound less fatiguing. At the same time the bass may be a bit much if you want a more neutral signature. Check out the fa4 thread for more impressions about them if you are interested.