We stayed at the Best Cambrils last Sept., and thought it was a very nice hotel. The location was a bit far out so caught the bus into Salou which was no problem. The rooms are average size but would be cramped with 4 in. Small fridge in the room also.
The food was very good and I would stay there again but the Costa Dorada was not for us. I would class the hotel more a good 3* rather than a 4*.

Can't really comment on your other choice of hotel but reading Travel Republic reviews it doesn't sound too good.

Hope this is of some help.