Originally Posted by Jancker

I have stayed at the Radisson twice and both times I used my free nights from the stay 2 get 1 free promo they ran. Once for 4 nights, once for 1 and I got upgraded to the suite on both occasions which was pretty sweet.

So my experience is only positive, can't say I did much in the hotel, so can't comment on breakfast etc. but the roomservice if ordered from the restaurant (not the roomservice menu) was excellent and reasonably priced.

Good location although not really near near a metro station. Located in a nice area with nice bars, you just walk up the hill and you are in the middle of it. Can only recommend it.
Stayed in the Carlton twice when it wasn't under the Marriott brand, so probably not fair to comment. Got robbed in the metro before even getting to the hotel so that whole area left a sour taste in my mouth, a lot of pick pokets around Atocha, especially in the metro, so watch out (regardless which hotel you choose)