I am well aware of Britannia's reputation, and certainly many of their hotels are long past their best.
However, all my stays have been excellent.
I knew to expect coach parties, bingo, and slightly run-down facilities. For the price, I was happy with that.
In fact, the rooms were of a decent-size, clean and in good condition for the age. Most staff are jolly and upbeat, some are quite surly, but I am generally just amused by that - it's part of the fun of a British holiday! I was quite happy to go and sit in the bar for half an hour while the bingo finished!
If you have paid a lot of money, expecting a 'grand' hotel (as many of them once were), then I'm sure you could be sorely disappointed. And, if you get the wrong room and / or staff, I'm sure that could also make for a miserable stay.
But if you expect a few rough edges, you may be pleasantly surprised.
(To be fair, at the Grand Metropole in Blackpool I paid £32 for Dinner, Breakfast, bottle of wine and a Jacuzzi room, so I would have been happy as long as the room had a roof!)