Originally Posted by dksix

Changing out stems (and seat post and saddles for that matter) isn't really a work around but rather part of the fitting process. From what I understand it's one of the common benefits of buying from a LBS, they often will swap out those parts from free as part of the basic fitting with the sale of the new bike.

I'm a newbie too when it comes to buying online, fitting and understanding the sizing. It's amazing the difference 10-20mm of stem length and or seat adjustment does make. Like I said I went from a 60CM to a 61CM and that 10mm difference is huge when it comes to the roominess on the bike but it's 2 different frames so every proportion is different so it's really an apples to oranges comparison. The effective top tube difference between the 15 and 17 size of your bike is 16mm and the head tube is 10mm taller. Swapping out your stem for this one SPP Bicycle Stem 25 4 x 1 1 8" x 95mm 25 Degree Rise Steel | eBay is probably going to do more for moving your bars up and forward than the 17" sized bike. (if I'm missing something I'm sure someone will correct me.

I'm not trying to talk you into changing your mind on going to the bigger frame just wanting to offer my thoughts on possible options. It's the general consensus that smaller bikes can easily be made to feel larger but little can be done to make a bike that too big feel smaller.