I wore this for my last track day, and it was wonderful. I forgot I was even wearing it. Flows air nicely, and moves with your body quite well.
shoulder straps do come off if you find them uncomfortable (I didn't have that issue).
One tiny negative is waist straps do not detach if you wanted to try and put it in your jacket.
I am 6'1" and have a XL, I would recommend going one size down though cause it is slightly to long for my torso.