Originally Posted by Diplomatico

I suggest just taking a taxi. The "all in" fare should cost you somewhere between 275-375 THB; of that, 50 THB is an airport surcharge that will not show on the meter (so don't be surprised if the meter reads 200 and the driver tells you 250) plus whatever tolls you encounter enroute (generally 50-75 THB, depending upon the route.) Most drivers will want you to pay the tolls in cash as they occur, not when the ride is over. If traffic is heavy, the fare will be on the higher end of the estimate; if traffic is light, on the lower end of the estimate. Make sure the driver uses the meter - state that when you get in.

If you take the train you'll be going up/down at least one relatively steep flight of steps, probably two. I'm not positive but I think your hotel is about 1km from the nearest BTS station. Not a long walk but not one I'd want to make after spending the better part of a day in airports/flying, especially when taxis are relatively inexpensive and with two bags in tow.