Yeah, the Domane's have a sloping top tube which makes sizing weird to me. From
Trek's web site:
If you’re between sizes, it’s generally best to go with the smaller size. It’s easier to make a smaller frame fit a little larger than vice versa.
I was supposed to pick-up the bike yesterday (a 56 cm Domane 5.2), but the mechanic who was assembling the bike said he wasn't happy with how it was shifting and didn't want to give it to me until he could speak with Shimano and find out what's going on. Because of the shifting issues, I wasn't able to actually go through the bit fitting process to ensure the 56 cm is indeed going to work.
Oh well... better to be working through these issues now while it's too cold to ride anyway than when it's 70 degrees out and I'm itchin' to ride!