They seem like opposites for having so much in common. I got my firebolt and the aggressive posture meant I had to learn to relax before I could ride comfortably. On the take off your stooped forward, arms bracing you with white knuckles holding on tight. It was only after a while, that you learn to keep your abs tight to take the pressure off your arms and wrists... and arms straight/or elbows flared becomes arms coiled/elbows back and tucked. You eventually relax a little and feel kind of like a lizard laying on a rock as you drape yourself over the top of the airbox cover in a tuck... which makes longer rides easier.
I only sat on a lightning after I had been riding the bolt for a while and found myself subconsciously leaning forward, I would imagine that would happen even more if I got the bike up to speed and leaned into turns even if not really necessary. So it seems like learning to relax when forced into an aggressive posture vs. leaning more aggressively while allowed to sit in a relaxed posture. The latter is probably easier, especially if you want to just kick back, take a hand off the clutch and cruise a little bit, victory-lap style. On the bolt, I will lean my left forearm across the airbox cover for a break on long stretches of empty road (not very common in NYC)
I split the difference and got drop pegs for my bolt. It aides in the relaxation for me in that I can use my legs more in absorbing shocks, push my butt further back on the seat (so you don't have to go full hunchback-- probably even better on a lightning with more seat) and press my legs against the side of the tank when turning or leaning.