Depends. I often commute on my tourer, less because of the more relaxed position than because it allows me to carry clothes, laptop etc. If I had to keep just one of my bikes the tourer would be it, precisely because of its versatility and all-day comfort.

For long distance rides on which I want to go reasonably fast I have a Giant SCR carbon (the predecessor to the Defy Advanced) which I use in preference to my Giant TCR because it has a slightly longer wheelbase, more like a Roubaix; and I'm getting a bit old and inflexible to be comfortable on the TCR for 100 miles at a time.

And for JRA, and as a winter bike, I'll use my fixed gear, which apart from the brakes (I'm very un-hip) is set up pretty much as a track bike.