its not about mods quantity, but quality. if mods quality doesnt match to other, why keep that mod?
without GT, there is not much left in IC2 to be bothered with. UE mods have almost every aspect if IC2 covered, but with better style, and i`m sure missing bits will come together later .
if you ask me, i`d like to see a ftb ultimate with UE instead of IC2>
I wouldn't say that GT isn't a quality mod, but i might be a bit biased since i probably wouldn't even play FTB without it... UE is a really great mod but doesn't really replace GT as they are focused on completely different aspects, replacing IC2 in a non-GT FTB might be a great idea!