I never felt that the partition severely restricted my seat positioning, but I'm 5" inches shorter. At 6 ft. I have 3-4" of clearance overhead, seat rails are 1 click forward from rear most, as I recall ( I drove without the partition briefly ) and I have about a 1/2 inch behind my seatback. Sure, you can't recline to take a snooze; but my seating position has been 100% comfortable for even 16 hours behind the wheel ... and I can't imagine driving reclined more than I am. Anyway.
The key points about this partition are that you need extended storage seat bases, the cross beam on the seats that goes side to side and an extra metal piece on the ceiling.