I owned the westone 3 and UE900 and I wasn't a big fan of the W3's SQ towards rock/metal. The bass seemed to subdue the mids (IMO). But I really liked the fit and ergonomics.
I think the UE900 is the better option among the two for rock/metal. It has very good bass, but it isn't overpowering. I sold my W3 am currently using the UE900s.
I actually preferred the GR07 if I was in the mood to just rock my brains out!
Just curious, were you using silicone or comply tips in the westone 3? The UE900 seems like a good choice as well, there's one thing though, people say it has a warm sound but I prefer a brighter sound with elevated treble. I'll check the GR07 out as well.