I recently got a deal on a barely used TH-500 and matching SL112 cab on Craigslist and have used them together and separately on a number of gigs here in NYC where I was relying on the subway and needed light weight and portability.
I am very impressed with the TH-500. It's a great little powerhouse, very light weight and can get close to vintage Ampeg tones with only a little fiddling.
The cab is also really nice, and also tends to lean toward a vintage-y flavor. Don't expect miracles in the volume department from a single, ultralight 12, though. It gets loud enough to compete with a drummer, but only barely.
A friend of mine has the Walkabout Scout and she gets really good tone - and volume - from that rig. More modern sounding than the Aggie stuff, but equally impressive.
I also use a 1x12 cab from Don at Low Down Sound. It's not neo, so it's fairly heavy, but that sucker is plenty loud. I've used it for rock gigs with no problems. It's also got a great, even tone. Just another avenue to investigate for you.
"People don't realize it, but the bass player holds the whole thing up like Atlas." -Some wino who talked to me on the subway on my way to a gig