Hi there
Southamptons nicer areas are of course .. nice! and I remember certainly a decade or so ago some of the people I know there would trumpet how it was voted one of the nicer cities in Europe... or something along those lines!
As it's a seaside town, on the south coast of the UK yes, it's a nice place! of course it has it's usual crap areas and the like!
I personally would'nt say it has 'good' proximity to London. The UK is used to much smaller distances and as such anything over 10 miles away is considered 'far' ! In real terms though, yes, getting to London if you need to is quite easy and relatively quick. Cost of living as per the UK as a whole is high, it's not perceivably any different from most other towns/cities it's size in the UK, most things cost pretty much the same as a town 200 miles away for instance. Certainly for housing/rentals etc it's not like its 'oh wow it's cheap' or anything. In the nicer areas, you'd certainly be paying a similarish amount to a place on the outskirts or just inside of London for instance.
You have a better 'chance' of better weather though!
Nightlife is quite good, um, theres plenty of err, hazy nights I remember when I used to visit friends who were studying there !
Do a little more research into the place but overall, thumbs up!
Cheers, DtM! West London & Slough UK!