UPDATE: the public taxi queue has been moved back to level 1 (down 1 floor from the arrivals area).
They have made the queue much more efficient - there are now 4 counters that process requests which are manned according to the peak arrival periods for flights during the day. I arrived last night at 10:30 pm and they had 2 counters open. I only waited 5 minutes to get my taxi in a queue of about 20 people, so efficiency is much improved.
There seems to be stricter regulation now, with no discussion from the taxi driver about whether or not to use the meter. He simply switched it on as soon as we started off and I gave him 70 Baht to cover the tollway fees. Grand total for the trip including toll way charges and the 50 baht airport surcharge was 320 Baht. I tossed in a 50 Baht tip as he did not drive like a maniac and we still got to my hotel in around 20 minutes. The official slip from the dispatcher clearly states that the fee will be meter plus 50 Baht airport surcharge and tollway fees to be paid by passenger if that route is taken. If the driver does attempt to negotiate a fixed fee, you can report him to the number on the slip.
No sign of illegal taxi touts as the airport continues it's clean up campaign.
During my last visit the taxi driver took my taxi slip and placed it on the meter in such a way that the displayed is blocked by the slip. By the time I notice this we were already driving on the road. I asked "Got use meter?". The driver gestured to the meter and said "meter, meter" but I can see the display wasn't moving at all during my trip. I paid the toll fees but when I reached Majestic Suites he asked for 400 baht so in total I paid 470 baht.
The official slip has the name of the driver and his taxi's license plate number and on the reverse a complaint form. I filled out the form and posted it. Thank goodness the post office is only a 30 second walk from Majestic.
So the moral of the story the taxi driver can still cheat you even with the official slip. And you are at their mercy once the taxi has moved onto the main road because the last thing you want is a pissed off taxi driver dumping you somewhere along the highway.
Seriously, I did not face such problems 5 years ago. The taxi situation seems to have gone from good to bad. Also try taking a taxi from Amari Boulevard....no one wants to follow the meter.