Newbie- Tell me more than smooth ride and extended wear

I have been reading the posts and I am about to make the move to the darkside.
I have read about the tires that will work and the mods necessary for some and also how smooooth the ride is. Which I am looking forward to.
I have an 03 1800C
I think I have a tire selected, Goodyear F1AS 205-55-16 but my concerns are without changing the final drive to a 1300:
Speedometer accuracy
Decrease in Milage
Higher RPMs cruising between 70 and 80

I also wonder, if I am going with a 55, will the back of the bike be that much lower to the ground and make a difference in confort riding solo and 2 up.

Any Thoughts?

I have a 205/55 and I don't think that it's that much lower. No issues 2 up, but I'm 200 and my wife is about 120, YMMV. But if low is a problem, certainly go to the 60 or 65, and then you don't worry about speedo accuracy. I don't think any of them will change your mileage enough to even really notice (Unless you calculate based on the odo number, and don't take the error into consideration) LOL.

I have to change my tire half as often
Tires are much cheaper and better selection.
Grip: Tire traction is 10x better, especially in inclement weather.
Speedo is innaccurate all the time. Get a speedo healer if you want it to be accurate. Then tire size won't matter.
MPG is the same or better.
RPM depends on tire size. But at cruising speed it makes no difference.

My 2 centavo's.

That tire has an O.D. of 24.9" and stock is 26.02" so there's your height difference. Good Luck!

the 205/65/16 is the closest to stock height, if you are going with the 1300 final (I have one, but it's only a few hundred RPM difference from what I have been able to gather) you ought to think about the 65 profile tire.... you are going to gear yourself down with the 55 profile and only slightly correct for it with the 1300 final... if you want to try and get any gains out of the 1300 final, get a 65 series. If you want a drag bike, your doing better with the 55 and no 1300 final.

Depends on what kind of riding you do. Trips or light to light....