I've been experimenting with both. I thought of using Session for my professional portrait and commercial work (shoot, edit, output, done), and catalogs for my stock images, fine art and personal projects which are an ongoing process. My problem with sessions however, is that I really don't need all those separate folders. Capture I understand if you're shooting tethered. Deleting images to only end up in the Session's Trash folder just means I have to delete them again at some point. If I delete them once, I shouldn't have to again. I only keep the ones selected by clients, so don't need to keep a Capture folder. If they're not selected, they're deleted. And as far as output goes, I prefer to stack the images as per LR rather than place them in a separate folder. In a LR stack, I can have the original RAW, a "Master" retouched tif or layered PSD, and then clones or variants of the Master. With one click on the stack, I can see all the versions without having to jump from folder to folder. When I output a file, it is only for delivery. I don't need to keep these as I can easily export the image again, as David says in that blog post.
So, the jury is still out a little on the Sessions, as much as I'd like to use them, I wish I could just get rid of the canned folder system and have my images in one folder, but stacked if need be.
As far as the cataloging goes, I haven't used it much. I love the RAW processing of C1, but there's a few things missing in the Catalogs that I'm not sure I want to live without and keep going back to LR. One, is the simple fact that I can't use the Julian Date as a naming token. All my images since going digital in 2000 use the naming convention, YYxxx (with YY being the current year's last two digits, and xxx being the Julian Date of that year) and the original numeric suffix of the image. So, an image taken today would be 15264-1234 with the "1234" being taken from 4 digits at the end of the filename. I can't do this in Capture One.
There's a couple of other things I'm working through, but don't have time at the moment to test it further. After Christmas I'll spend more time and try to make it work again.