I've got a Marshall JTM C410 cab, loaded with G10 Vintage Celestions which I've been using (gigging) for over a year. It was cheap (I bought it with an amp, but say £100 plus what I paid for the speakers) and those who've heard it have said the bass is superb, equivalent to a good 2x12.
It's also a damn sight easier to tote around than a 2x12, being narrower, and I reckon it does most of what a 4x12 does, in terms of spread, overall waft etc.
Highly underrated for pub giggers.