I have grabbed several F(O) awards on LH this year.
All using UA miles with saver awards at T-14 and less.
IAD to FRA (Old F)
FRA to NRT (A380) and only two people
JFK to FRA (A380) and return twice this year
And I just booked a return on FRA-EWR On what looks like New F.
I know it stinks to have to wait to T-14 but always got the dates I wanted and wouldn't have a problem going +\- a day if it meant LH F. The serving is always absolutely amazing.