Not yet mentioned is the resulting fit that just swapping from drop to upright bars gets you. Yes, your upper body will be a bit more uptight. Your neck will have less angle to see forward. Your hands will have less upper body weight on them. But with that more upright upper body will come a loss of power one can apply to the pedaling. The usual fit for upright bikes have the seat set back WRT the BB/pedals a bit more than with drop bars. Sometimes there's enough seat rail length to reposition the same seat (and post) rearwards enough to feel right. Sometimes not so and a post with greater set back is wanted.

Then there's the change as to how wide the contact area is, between the seat and your butt. As you sit more upright and your butt rolls to follow, the butt's wider area is contacting the seat more. Often a different seat is discovered to be needed too. Many don't see this far past just the handle bar differences they are wondering about. Andy