Hi Gary
I haven't stayed at the Sheraton but I know where it is. I think its just had a lot of refurbishment done. I've stayed at the marriott which also had a shuttle boat to get to the "right" side of the river. Yours would be a very short hop and you are at an ideal location. You have the sktyrain there and also the river boat main stop, where you can get the tourist boat or any of the express boats. The only real problem is that the shuttles stop at midnight( and i think the skytrain stops not long after) so you would need a taxi for late nights back. This might seem easy but its amazing how many blank faces you get when you ask- so make sure before getting in. We even took a hotel card with Thai writing but it often didnt make much difference.
Its a very fancy shuttle boat by the way