Hi all -

I'm booking a flight in October that basically looks like this:

DEN -> IST
KBP -> DEN

I see the same fare on both United and Lufthansa, about $1280 which is fine. But, I am trying to figure out where to book the flight. Can anyone tell me if I'm understanding this properly:

If I book in UA: It looks like I'll get 100% miles for the flight, but I can't do seat assignments (which I don't really like because I'm tall and finicky)

If I book on Lufthansa: It looks like I'll get 50% mileage for this flight (I think) and I can pay extra for assigned seats.

Note that I only have a UA Mileage Plus acct, I don't actually have any miles on Lufthansa. In the past, I've always been able to get a decent seat on these flights by checking in exactly 24 hours ahead and just grabbing a seat online, but I'd sure like to reserve in advance. Then again, I hate to give up miles

Any advice here?