For reasons I won't bore you with I found myself over the last month staying at a lot of the hotels and some B and B's in Cardiff. Here's my verdict on some of them.
Park Plaza - very expensive, though this did include various add ons like the gym that I didn't use. About what you would expect.
The Thistle - Very expensive and if I'm right they charged for the internet on top. Didn't even have a bath! Over-rated.
The Maldron - Very pleasant, nice colours and more reasonably priced that The Thistle.
The Royal - Decent price for a classy place (obviously there's some work going on there at the moment) and a nice sized bathroom. Good value.
The Lodge - Very run of the mill accomodation. Adequate.
Sleeper - Very poor. The worst place I stayed and by no means the cheapest. Not for people who are clautrophobic. About double what would have been a reasonable price.
The Sandringham - A real surprise. There are no lifts and the stairs are pretty steep which could be a problem for some people. Might seem a fairly shabby hotel but the room itself was excellent. Makes the two stars go a long way.
The Big Sleep - Unconventional hotel and clearly 'budget' accomodation. Nothing fancy but overall good value even if internet charges are extra. I still think it looks hideous on the outside though. And I could have done without the John Malcovitch pictures, bit spooky.
Ibis Budget - Very 'modern' in it's way. A fair amount of room though frankly pretty minimalist. Certainly better value than Sleeper.
So if you want something fancy I'd say The Maldron. For more budget accomodation it would be the Sandringham or The Big Sleep.
I find the Big Sleep curious and foreign people (French) love it - Sleeperz good but yes small and expensive. One of the best values is Premier Inn on Western Avenue - great room very classy huge breakfast and really excellent value for money if you get the £29 a night deal -
Future inn down at the bay is great too but pricy
Travelinn @Llanedyrn (if that's how you spell it!) good value and clean - not to be confused with the one in Whitchurch!
I don't have much need to stay in a hotel in Cardiff. But if I did I would like to try the Jolyon ones to see what this boutique status actually means in practice, and the Radisson on the hope of being high and getting a good view of the city...