I'll weigh in. I've got positive and negative experience with both. They are still computers when it comes right down to it. I'm typing this on a Gateway Tablet right now. Yes, my company has done a fantastic job of guarding it with software that is constantly using up my RAM, but I haven't gotten a virus yet.
InDesign crashes here and there, but its my own fault for letting a file get too big before "save as". This is a little hoodoo that I have learned since working with graphics files on the PC.
I have wiped an iMac Graphite and an ibook 800mhz down to 0. What a liberating experience. Both of the them run amazingly now, and have for over two years. No issues whatsoever. Partitions have been good to me. I am about to max out the RAM on the ibook and load Ableton Live on the ibook, which will really test the processor. The ibook has been banged around quite a bit too. Good little computer. I like it a lot.
I also like the Gateway fine. Sounds funny, but it has been great so far. InDesign and Photoshop, Excel, and (gulp) Lotus Notes are pretty much all that I ever run on this thing. Seems to be fine.
Did anyone notice the optical audio output on the new Macbook?