We went to Benidorm for the first time last year with my daughter and her family. They had booked it and then a few days later asked if we wanted to join them. (not for baby-sitting of course !)
Anyway, the hotel was as it said on the tin; a 4 star Thomson all inclusive. Food was great for the first 4 days then we were fed up with it. The drink, apart from the very weak spirits was really good. Full bottles of cava and wine available and not just by the glass. So needless to say, we had our money's worth.
We did venture out most nights and was pleasantly surprised how cheap the drinls were in most of the bars. Lots of special offers.
However, I wasn't impressed with the entertainment in the Old Town. NO real live bands as far as I could find. One man or duos at best. Certainly wide variety of acts available from clowns to strippers. The Talk of the Town is worth a visit. The resident compere is an old pal of mine (although his pseudo English accent would tell you otherwise) At least three acts on every night. Good service at the bar etc.
To summarise, I wouldn't hurry back. The Old Town was too wild and the Old Town was too quiet. It did make me see why I enjoy Tenerife so much. Not my cup of tea, but obviously very very popular.
PS the beach and promenade were lovely.