think its important to note that the gym is pretty small and does get very busy at certain times of the day... 4 oclock onwards mostly. and as already said the price you have to pay varies depending on the time you go (if you pay the £28 member ship fee) as far as i know, from what i've heard, the free weights section is very much dominated by rugby players, which a lot of people find quite intimidating. my housemates once went in there, and were later questioned as to what two girls were doing in the free weights section.
i joined a gym, about 10 minutes in the car away, it was £15 for a months trial membership, which included classes aswell. although it doesn't have a swimming pool, it does have a steam room/sauna and not that many people know about it so it never got that busy. after the first month, it was £20 a month, which you could do for 3 months at a time. i personally MUCH prefer it to the uni gym!