I stayed at the CY right around the corner last month. So I didn't try the Ren pool, but the location of the Ren is excellent, depending on what you plan on doing. Lots of restaurants and shopping nearby. It's connected to the BTS, so minutes from almost everything. It's a little bit of work go get to places like the Grand Palace or some of the famous temples, but that's true of any hotel if you're not staying right on the river. I'd risk saying it's one of the best-located Marriotts in Bangkok.