Originally Posted by ISTFlyer

For this part, I wouldn't comment but would mention was spot on



To be honest, 9 hours is a pretty decent cut-off time as assuming that you have arrived on time and clear immigration, go to the hotel desk and being transferred at your hotel within 1h30mins after landing and picked up from the hotel 3h30mins before departure. You would have minimum of 4 hours of rest time at the hotel which would be in addition to the rest you would get on the flights. Also there are only a couple of sleeping rooms at both lounges, thus as you mentioned they could get easily overcrowded. Maybe the situation would be solved depending on the format of the brand new Exclusive Lounge which is supposed to open in the upcoming months as TK say all the time but for the near future I don't expect things to change.

So, during a schedule change over 15 minutes, you always have the right for a refund and change of dates within -7/+30 days without any fare difference. If you are unsatisfied of your layover or would like more sleep, you could prefer another airline with more decent layovers or pay for the sleeping pods, YOTEL or use the lounger chairs at the lounge but it's the reality that TK is quite generous here as if this case was on another European airline ( with a quite few exceptions like LH First & HON having rest rooms at FRA & MUC ) or a US carrier, you wouldn't get anything more than free lounge access with lounger chairs while TK is at least offering you something. Leave that aside, some other carriers would refuse you to refund or change your flights if you have a schedule change of 3 hours 59 minutes unless you pursue legal options.