Venge and Roubaix are two completely different bikes.
Everyone is different, but in general, the Roubaix will be more comfortable for longer rides.
Go to your LBS and test each one. You may find the Venge fits you perfectly.
I really like my Roubaix, but I've only put a few "real world" miles on it. So far, I love it.
There are a few rough spots on my route that are significantly less noticeable than they were on my Allez.
My only problem is not frame related.
Either the saddle or the way the saddle is set up was putting a bit of pressure up in my junk. Not very comfortable.

Hope to get it straightened out next week.