never expiring miles? great! In which areas do these flights operate?If you don’t have any plans or are uncertain, transfer to United and you can even take advantage of the excursionist perk.
I am thinking of transferring to united as it has the most options and a reasonable mileage requirement. I think the flexibility it offers along with never expiring miles is the best option. Rather than tying up miles in Turkish which is useful for Europe & US; or Singapore airlines which is useful for east Asia.