You can't beat the cobble gobler seat post in my opinion -- and the Zertz inserts are not night and day, but over a 2 hour ride, the dampening adds up.

That said, They both will come with a 25mm tire -- and the 28 will fit on the Roubaix, from everything I have read. I don't see a reason to change the tires, unless you're going on towpaths with lots of half-buried rocks, etc.

They both have the 50/34 and 11-32, so that's a moot point. Both come with 700x25.

At the end of the day, they are very similar. I don't think you'd be going wrong with either choice. For me, it would come down to the bike shop, and even what color I liked better...or how big or a hurry I was in and if someone had my size/color in stock and the other didn't.