Take a look at this trip report from December:

http://www.flyertalk.com/forum/trip-...nbul-b777.html

Turkish is known for their food, and the business product is full flat, albeit not all aisle access. If you get a 77W, make sure that you don't get stuck with a middle seat in the 2-3-2 layout. You can call ahead about 100(?) days before your departure to select seats. Consensus among people that I have talked to is that they prefer the overall TK business product over UA and Lufthansa, but not Swiss.

The lounge in Istanbul is AMAZING. Google "Turkish CIP Lounge" for pics.

Only caveat of taking TK to Europe is that you overshoot your destination a little when you layover in Istanbul, making for longer flights. Although I haven't experienced IRROPS myself on TK luckily, I've also heard that they are a bit less adept at handling them than the European/American carriers.

If your layover in Istanbul is long enough, look into the complimentary tours that TK offers of the city here: http://www.istanbulinhours.com

Based upon what fare class you book into on TK, you can check what mileage you'll earn with United at the link below. Although, you can be rest assured that you will never earn less than 100% with any business fare on TK, even the discount ones:
https://www.united.com/cms/en-us/mar...spx?itemid=306