Rock, Blues, Metal helps a little, but I play that, but maybe not like you--and I'm not satisfied doing all three with the same amp. Also, do you play rock 60% of the time, Metal 35% and Blues 5%? Does rock mean the Who or Van Halen? Those are really big differences. I'd really prioritize on getting the amp for the sound that you play most, and then secondarily try to pick up the others.
If you are open to other suggestions, here's just a couple of suggestions:
Peavey Classic 30 watt 1x12 combo (I think very versatile with some great sounds)
Marshall DSL15C 15 watt 1x12 combo (If you want discount all-tube "British")
Or for a little more (save a little longer or buy used):
Fender Bassbreaker 15 1x12 combo (A very nice middle of the road, can do a lot, but not either extreme well)
Peavey 6505 112 60 watt 1x12 combo (great for hard rock and metal if that's what you want most)
EDIT: I know a lot of people like VOX. I've never found one I liked, but you may love it.