Cheltenham sometimes has an undeserved reputation for being overly posh. I’d say that yes, it has its posh parts, but on the whole is no worse than any other similarly sized spa town. It also has some rough parts, but these are easy enough to steer clear of once you know where they are.
Wouldn’t live in Bristol and commute up, no chance. In fact I know people that do the opposite! Cheltenham is a much nicer place to live than Bristol, in fact the only thing I’d say Bristol has going for it over Cheltenham is if you were young and single and wanted a banging night life. Cheltenham is a little more reserved, but is still much better for a night out than most places, with more variety and a more friendly atmosphere on the whole.
As for cycling, well for some reason Cheltenham has more bike shops per head person than any other town/city that I can think of! The Cheltenham & County club is huge (if clubs are your thing), but I know a lot of people that have nothing to do with the club and still ride lots in and around Cheltenham. Cycling is big there basically, so don’t worry on that front! And you’ve got FoD, a417 project (coming), the Cotswolds etc. all within spitting distance…
I’m from about 12 miles north of Cheltenham originally, and most of my extended family gravitated south and have ended up settling in Cheltenham, including my sister. I’d live there if I could, but my business is in Droitwich and the GF works in Brum, so we have to make do with Worcester (which is ok, but very dull and lacking in any form of excitement compared to Cheltenham).
If you’ve got to move somewhere for a job, I can think of a whole lot of places far worse to move to…