Basically I am in a position where I can buy a Vox AC30C2.

Anyone out there who's got a good enough argument to stop me buying it?

I figure I better get a final round of approval
Classic rock basically. Queen, Zeppelin, The Who, Rolling Stones etc.

With a Brian May Guitar.
loud is not the word for one. Make sure you EQ it right, otherwise it can be shrill, they are brilliant though.
It'd be a good amp for most of those bands. maybe need a pedal for zeppelin, but i dunno.
Just buy it already!
Gilchrist custom
Yamaha SBG500
Randall RM100 & RM20
Marshall JTM45 clone
Marshall JCM900 4102 (modded)
Marshall 18W clone
Fender 5F1 Champ clone
Atomic Amplifire
Marshall 1960A
Boss GT-100

Cathbard Amplification
My band
I got some pretty sweet Zeppelin tone out of it at the shop, and that was with about 5 seconds worth of playing around with it, so could get even better.

But yes... I shall buy it soon! God it shall be good to upgrade to that from a Spider III 15w...
Good sound for those bands. You will definitely need a pedal to get good gain tones out of it (its REALLY loud when you crank it...don't let the 30 watts fool you).
Suhr Custom, Flaxwood Rautia or Grosh Tele thru
HBE Medicine Bawl Wah
Analogman BiComp
Texas Two Step OD
Fulltone Ultimate Octave/Fuzz
Boss CE-2
TC Nova Delay
SLO-100, 65 London or Bogner Shiva
Ask me about any of this stuff!
I played a C2X and loved it. That has different speakers though. I also like the CC2, upon which the C2 is an upgrade in terms of speakers. Can't go wrong tonally.

In terms of construction I've heard that the AC30s can be a bit of a pain, and with the C2 in particular that it's made of MDF or some other similar material (not decent wood/plywood) which isn't good enough for an amp of that price really. Searchbar some of the other threads on this amp and you will find the kind of info you want.