So my MacBook is well over 3 years old and it's starting to get really aggravating. It's actually still plenty fast, but the original Unibody MacBook seems to have various I/O problems, and I've ended up only using this as a glorified netbook for a while anyway. Meanwhile, OSX Lion is starting to really get on my nerves for a number of thousand-papercuts reasons, while Linux has been getting progressively better and better over the last few years.
So anyway, I've been looking at laptops again and have a pretty short list of ones I'm interested in, but am open to other suggestions as well.
Right now my top contender is the Lenovo ThinkPad X220T. It's fairly lightweight (about 4 pounds), has a convertible tablet screen (multitouch and Wacom) which makes it useful for a lot more things for me, it apparently gets pretty decent battery life (5 hours with the standard battery, and there are additional batteries you can add on to get it much higher). Also, being a ThinkPad it's very well-constructed, and has a decent keyboard and touchpad (and while I'm not a fan of nipple pointers as a primary input it's nice as a backup). On the downside, 4 pounds is probably a bit too much for the tablet to be particularly comfortable, and a 12.9" 1366x768 screen seems positively anemic these days.
In second place right now is the Thinkpad T420s. It's a little lighter than the X220T, has a bigger screen (14" 1600x900), and has a real GPU as an option.
In third place is the X220, which is exactly the same spec-wise as the X220T except there's no tablet functionality and it's quite a bit lighter (under 3 pounds). It seems to be the perfect blend between netbook and laptop (and isn't much more expensive than a netbook, either), but the fact that the X220T exists makes me feel like I could be doing more with something in that form factor. But the plain X220 is definitely better when it comes to having something I'd not mind traveling with.
Other than the three ThinkPads above, I've been looking at a bunch of the various ultrabooks, but many of them suffer from crappy keyboards or touchpads, or are a bit underpowered, or reportedly don't run Linux at all well. And of course now that I know about the X220T I'd really like a convertible tablet, but most of them just plain suck. I just wish it had a bigger screen.
Are there any other systems I should be looking at? I require Linux compatibility (I will probably dualboot with Windows 7 for a while though), Core i5 or i7, I'd prefer to keep it under 4 pounds (and the lighter the better), a good keyboard and touchpad, and a screen that's at least 1366x768 but larger is better, and a Wacom stylus would be a nice plus. Per those criteria, the MacBook Air 13" is actually a really good choice, except I know from experience that MacBook touchpads are hard to get working well under Linux (where multitouch support is still in its infancy and everyone seems to think that tap-to-click is the only thing you need).
Anyway, are there any other systems I should be looking at?