Southampton wall is pretty terrible. The university has a bouldering wall which is better although I think you might still be dissapointed, but if your desperate for a fix then it is OK. No campus board though.
If you want to go then I would recommend posting on the SUMC facebook page to get someone to show you where it is/ sneak you in...
The bouldering at Reading centre is worth the drive if that's feasible.
Chris