Have stayed there twice in the past year. Although the location is not central, taxi's are cheap & plentiful to get around if need be.
As for the hotel, the public areas are very nice, in a modern but not minimalist way. Bars, restaurants etc are all pretty good & the main bar is a fun & lively place to be most evenings (esp if you are there on Grand Prix weekend).
The rooms however have not received any modernisation since the hotel opened (1992 I think) & look pretty tired now compared to other 5* hotels. Eveything works fine in them, but the carpets are a bit tired, the bathrooms dated etc.
All in all, it's still my favourite hotel in Barcelona for the feel of the place & the views.
Have also stayed at Hotel Omm......this is not a luxury hotel, it's a 4* trendy hotel with poor attention to detail, badly trained staff, bad soundproofing & a rubbsih night club!