In no way, am I giving the Renaissance a bad rating. It was a wonderful stay, the rooms were very high end. Our room was a corner room with windows on two sides and a nice view of downtown Bangkok. The bathtub was very picturesque with a huge window to look out, though it looked into another building. The bed was amazingly comfortable and most of all, the staff was extremely helpful, from helping us so we wouldn't miss our flight to directions and restaurant recommendation, etc. The location was right in the middle of Bangkok.....nice!
BUT.....I would compare it to the Chatrium where we also stayed. Though the location was not as good at the Chatrium riverside, the view was better, the suite and bed was just as good, the staff just as helpful and it included breakfast. The only significant difference other than the location and number of stars was the price. The Renaissance was twice as expensive.
Now, this was my first 5 star hotel, so perhaps those of you that will use all the amenities and are not just looking at the room and general service, then you might find the price difference worth it. I did not.
Would I stay here again? Yes, if I got a big discount. But for the money, I'll choose differently.