Well, I reconsidered after I asked. I went back to the sizing charts and the difference in length was not one inch, as I first mis-remembered, but was only a half inch, which is how I ended up asking a kind of obvious question. I think I know the answer in that case -- maybe a little, not a whoIe lot. Could decrease the frequency of heel strikes on panniers some I guess. And it depends on the rider and what they're doing with the bike. Maybe a pro would notice?

I was just going to delete this thread but I didn't see how to do that. Maybe because I block Google JavaScript by default with NoScript, and since the site got reworked more of it seems to be relying on ajax.googleapis.com.

It's still weird to me that a frame would increase two inches in height but only a half inch in reach.