There's not a consistent and significant enough gap between the 3 to make any difference in terms of experience for me. It's really about availability and timing first and foremost.

The rest are:
-LH seating is worst for flying solo. (When traveling with wife, i dont care).
-LH has option of 747 upperdeck
-LX P earns miles to my program, LH P does not
-OS used to be most convenient to me, and also I like their coffee cup which I sort of collect as souvenir :P

Keep in mind the solo "throne" seats are specially reserved and you may not be able to get it for yourself.