This is a key point. I've never felt the need for suspension seatpost, but my bike with the most upright positioning is my fat bike, and on that I have 4" of rubber at low psi to take the bumps. On my other bikes I'm positioned such that using my knees up out of the saddle for suspension is a very natural thing. The bike I'm presently using as my commuter, a Surly Troll, has a Cambium C15 saddle, and I've found it really absorbs little road and trail irregularities well, even with 1.5" tires at 75 psi. So, as everyone has mentioned, there are many things you can do, but if I were riding upright at 65psi+ I might consider an inexpensive suspension post. I wouldn't actually get one, but I might consider it