the screamer is great amp for the price, very versatile and the only thing i don't like about it is that the tube sockets
are pcb mounted(weaker structurally) .
sometimes i have the urge to change or more like 'upgrade' but the problem for me is to find something with a great
CLEAN, crunch and overdrive(with chassis mounted sockets)
i've looked at the supersonic fender 22 which seems great but maybe not enough poke for you?
i've looked at the cornford mk series which is in another category.
i don't think there's much better in the price range of the screamer without giving something up( eg less great cleans traded off for a better overdrive etc).
the koch twintone's worth a look too.
just to remember how good it can sound(even on youtube)
"
http://www.youtube.com/v/BCHueoawVsc?