Still, what works for you works. If Ubuntu's doing the job for you, then congrats and have fun. Just don't make the mistake of comparing it to the Mac systems without spending a lot of time in each.
2) What? I don't think many people will agree with you on that aspect. The fact that most Linux crashes you can just reset X and be back at the login screen, where as a Windows crash needs a full reboot means that even if Linux did crash more often - which I don't think it does - you spend less time getting screwed
3) Really? I haven't found much of a difference on my Dell laptop.
and 4) Probably true
2) My Windows XP machine hasn't crashed once since I've had it (over two years). Ubuntu 6, 7, and 8 have all consistently crashed when resuming from hibernate on my laptop (Lenovo T60, one of the most common in the world).
3) Ubuntu 8 usually runs about 45 minutes to an hour less than Windows XP on my laptop's battery.
2) There are still reliability problems. I'd include driver issues as a reliability problem.
From my experience with it, it works great if and only if you can find the right drivers. When it runs well, I like it more than Vista and most likely more than XP. But XP is certainly more supported overall, and that's another thing that's definitely worth considering.
The keyboard on the newer computers is beautiful. I didn't like the old big keyboard: the new ones feel wonderfully responsive to me. The heat is a problem, but I guess I'm biased, because I rarely have my computer on my lap. I keep it on my desk or in my bed. And I use a fan program to speed up my fans when I need to, and it usually works.
The proprietary formats are a pain, yes, but that doesn't affect me very often. With iTunes, I get most of my music from other sources. I have perhaps 10 CDs that I got from iTunes, and that's mostly from Plus, so it's open enough to send to other people. Everything else is MP3 and MP4, which means - among other things - I can click and drag songs to iChat and it works.
The mail import took me a long time, for Gmail. But it imported my other emails first, and with Gmail it imported mostly the archived email, so I could use it right out of the box. I don't use Maildir, so mail works pretty much beautifully for me.
What does that optimization do for the fonts? Do you have an example? And either way, I'd take the Apple default fonts over anything else I've seen to date. I'd kill to keep Zapfino.
the optimization just gives you really nice smoothing (i wish i could upload pictures here). i currently use the android font on emacs 23 on a thinkpad (black on light blue) and i find it to be much easier on the eyes (the powerbook fuzziness gave me headaches)
anyhoo, enjoy. the hardware is indeed beautiful. and the new aluminum ones sure are tempting (but i'll wait until someone gets ubuntu working properly on them)
and not to beat a dead horse, i really tried _hard_ to get the powerbook to work for me. i was really determined to like it. but no dice: http://news.ycombinator.com/item?id=131930