Is there a specific reason why you are not considering United's Mileage Plus? You can book award flights online including *A partners. What is even better is their tax & fees on award tickets always beats TK's and I am sure it is the case against LH as well. Check UA's tax&fee pricing by doing some sample searches on the routes you are planning to use your miles on:

http://www.united.com/web/en-US/apps...archAward.aspx

TK is pretty bad for award tickets on *A partners. You won't be able to make it on the phone or on the website. The only way is to go to a sales office in Turkey. Even a sales office outside Turkey won't do it. I tried it in JFK, in Chicago, in Los Angeles and they all failed. Unless you are going to be able to spend the miles (with a reasonable fee!) what's the point of accumulating miles?

If you are flying all TK than you can make award redemption online. Even then good luck finding a reduced mile rate. I was able to find reduced rates on UA (30k) while TK (50k) was showing me not available for the same dates and flights.

The only reason I am staying on TK's flight program is because with their program both me and wife's mile earnings are gathered in one account as a benefit of being elite. Even then I am debating if I should switch over to UA because I can get award tickets for $5 instead of $400...