Glad you also had a good experience!
I flew back from IST on Monday (I was in 2A). Inbound was 55 minutes late but IST got their act together and did a lightening speed turnaround. Boarding was as you had said with CE first, and there were no queues at security (either to get into the airport which also has security or general security). The Primeclass lounge was actually decent for an outsourced lounge and had a bar - I didn't look to see if the drinks were included or if you had to pay extra for them!
The 767 was very lightly loaded which must make it easier, but our CSD (Gary S) did a good job of looking after everybody and even used names during the meal service, which is a rarity in CE!
He also had to put up with a very grumpy person in 3A who was upset about everything - basically we all got the message that he prefers Turkish Airlines. I thought he was going to blow a gasket when we parked at a domestic gate and steps were attached to the back of the 767, meaning that CE were the last off. At the door he was moaning about how it was a disgrace and how the captain should go down and tell "them" (Heathrow, I presume) that it is not acceptable. It isn't very good, but moaning to the CSD isn't going to change it.
Overall, I've certainly noticed that service from CC has improved this year, and I hope it is going to continue. I'm not sure if it is the "To Fly To Serve" stuff, if it is that a lot of people have left EF/WW (if they have) or if it is because Willie has gone to IAG and morale is better (or a combination) but things are definitely on the up cabin service wise IME.
Oh, and I had the lamb koftas, which were very good - possibly the best CE meal I've had this year.