I go for the best price and prefer direct,but that is only Thai and Norwegian that does that from Coenhagen ,and I often go near Songkran and easter so no cheap ticket there,its easier to get them near high season,but thats maybe there is more competition at that time.
I have try Tyrkish Airlines one time and that was ok to ,but didn't like the airport in Istanbul,but will use them again if the price and connection fits me.
Have a safe trip whoever you use.

