I guess I should give my 2 cents on this one.
I have a 2005 Trek xo1 and a 2006 Axis. Did my first year of cross races on the trek did ok. I bougt it in my normal road bike size. Wished I would have went one size smaller. Now it is my do everything bike. Mounted with a full time rack it is my comuter, it is the bike that hauls the trailer to the store Pics of it are on my blog) It has been toured with I have done more centurys on it then I care to count. Its the bike that is used when the weather is nasty and there is snow and ice on the ground. For the long haul I find it allmost as comfortable as my 5200. They only thing I have changed besides the chain and brake pads was the outer chain ring I think there is a 50 on it now.
The Axis is a race bike, it's set up as a 1x9. I bought it a a frame and built it up the way I wanted it.
The axis has more agressive geometery, and you end up witha more mtb feel. I think the longest day I have spent on this bike was about 50 miles or so. So I cant give you how it feels to ride a century on. I do like the way the squared off top tube feels when the bike comes to your shoulder.
If youre not going to race it or evan if you are. I would go with the xo1 as an all purpous bike.