I've been told, and it makes sense, that rear CG makes a difference due less tailplane drag. Got the chance to try it in a PA28 (which has a rather forward CG anyway. 2 on board, trimmed, I climbed down the back. Pilot re-trimmed, aircraft gained about 8kt.
Understand that airlines plan for long-range flights to be at or near aft limit on landing for this reason.