I attended Reading and really didn't like, but I knew a few people who attended Portsmouth and absolutely loved it.
That said I would still choose Reading, the fact I didn't enjoy is due to a combination of factors that was down to problems I had, not the university itself. In terms of what it offers students it doesn't excel anywhere (i.e. Oxbridge has higher acadmeic standards, the Manchester univesrities offer better nightlife and so on), but it is not deficient anywhere (it's acedmic standrads are higher than most universities, there is plenty to do at night, etc).
In terms of the town itself (which I know very, very well), like any big town there is crime and there are places not to go (avoid Whitley completely, avoid the Oxford Road at night), but Reading is a fairly affluent town and there are many, many worse places to live in the UK.