'Fast' track at IST last week was truly awful. Provided by 'partner' TAV, they have only one person on the passport desk (and three people on the desk to count the fast track tickets - honestly, three people who count them again and again, shuffle and count again). Electronic visas seem to have slowed everything down. Took 1 hour 10mins of queuing before the first CE passenger went through. In the meantime thee entire ET cabin had passed through the normal gates!
TK's business class queue was much better serviced and was quick.
Exactly the same experience on the way back - one operative and four to count the cards - you would think I would have learned.
'Fast track' at IST is not a perk, it is punitive. My advice would be that if there is more than four people waiting in the TAV fast track line, bin it and just join the other punters.