I worked at Our Price from 1989 - 1995. It finally went bust in 2004, and I have no idea what it was like in the final years, but the rot had already set in by 1995. The hierachy became so obsessed with competing with the supermarkets, that the choice they offered was reduced, it just became almost anti-music. We had to play chart music all day long, with certain cds having to be played at certain times of the day, I hated it at the end.
Went to Tower then, but not in a shop, in an office. Tower was run by music enthusiast, and virtually all of it's staff were obsessed with music, this is why Tower Piccadilly Circus was such a good store for real music fans. Unfortunately, Tower had no business model, no business plan, and no chance of ever surviving.
HMV I think was somewhere inbetween Tower and Our Price, but I think it lost it's way somewhere along the line. I hope it can survive, but I fear it will be bought, asset stripped, and then chucked away, and we the tax payer will end up paying for the staff redundancies a la Comet.