I arrived at Dong Mueng yesterday afternoon. My plane landed at 15:25. When we arrived at the the terminal, a guy from the FastTrack immigration service was waiting for me holding a sign with my name. I followed him through the airport to the priority immigration. I got a good look at the regular que for immigration and the entire hall was full...
Using the FastTrack, I was outside the airport in under 30min, so I'd say money well spent
Next, my contact showed me to my car and off to the hotel we went. The drive was also nice and relaxing and I was at my hotel at around 16:35.
Way overpriced. See my link a few posts back. About TB1200. I have used the same service at BKK twice and it is totally worth it. Much easier than crutches!!