Hi mate,
Can't comment on the Matrix Q12A, but from what I've seen here on F.Forum, there's a fair few folk that like the Q12A, but it seems as though there's more popularity towards the CLR. Having owned the CLR and not being able to gel with it, I'd throw a third option in the works and recommend the Friedman ASM.. that thing is awesome. Personally, I've found the CLR to be too 'spikey' in sound, which I found hard to dial out. You can't really remove it's spikey core tone, which, even though it's supposed to emulate a mic'd up cab, I don't really think it translates that well, and to me, it therefore sounds NQR and too artificial.
The Friedman sounds less 'harsh' on the ears more like a guitar cab.. So I guess it depends on what you really want your FRFR speaker to sound like. If you want it to, I guess, sound a bit more real, I'd personally recommend the Friedman..