i own a td660 and a fafner II. while i love the sound of the td660 i have to say that it is very much weaker than the fafner II, which to me plays in one league with a db750. just insane amount of power. if you really need power there is only one ebs amp.
the hd350/360 is a very decent amp, the design has no flaws, absolutly reliable, it has everything one needs and the tone is to die for. it has almost as much power as the td660 which is enough for most occasions - maybe not big open air stages. but there will be a monitoring system... perfect for recording and still relatively easy to move around.
in the eighties i dreamt about a trace elliot amp with 350 watts ... i tried a lot of class d amps and the only one that really convinced me is the blue soul.
go for the hd350/360, you wont regret it
Sandmann