Theoretically the capacitive touch should be more responsive but the screen should also be more reflective and slightly less sharp, but in practice the difference isn't that great either way. The Paperwhite is probably slightly more responsive to touch and the Glo has a slightly clearer/less reflective screen (because there's one fewer layer), but both are fine on both accounts.
The biggest difference IMO is that IR works with gloves on while capacitive does not, unless you have those special gloves designed for touch screens. Something to think about if you read outside. Also the Paperwhite has a two-point touch system while the Kobo is only one-point, so you can do pinch-to-zoom on the Paperwhite with PDFs or whatever, although eInk is laggy enough still that this could be a good or bad thing depending on what you're doing. I don't think this is a hardware limitation with IR though, since some of the Sony IR readers apparently had multitouch, so perhaps Kobo will address it with a firmware update.
Last edited by stewacide; 01-07-2013 at 08:05 AM.