The new Macbook Pro 15" Retina display scores 1/10 in iFixit's repairability guide. Link
here. Reasons for this very low score: the battery is glued to the chassis and also covers the trackpad cable. Attempting to remove the battery might break the battery and shear the cable. The display assembly is completely fused with no glass protecting it. The RAM is soldered to the board, and the SSD is on a proprietary daughter card. In short: when your batteries die, your Macbook will be tethered to the power brick for life support. You have no chance of replacing the battery.
The Macbook Air 13" scores 4/10 in iFixit's repairability guide. Link
here. The RAM is soldered to the motherboard. If your RAM dies, there goes your machine. The SSD is on a daughter card and is proprietary. At least the battery is removable ... once you get past the proprietary screws that Apple uses.
Bear in mind that SSD's have a limited read/write cycle. The SSD controller automatically maps sectors on the SSD as they grow bad, so if you use your SSD intensively (especially if you are in the habit of copying and deleting lots of files) your SSD will eventually lose capacity and need to be replaced.
Apple laptops look very nice, are built very well, and have some of the nicest keyboards, trackpads, and displays on the market. But unfortunately these do not mitigate their serious failings such as a non-replaceable battery, inability to upgrade the RAM, and proprietary SSD.
One wonders why anybody would buy a laptop with the battery glued to the chassis. Perhaps they don't mind throwing their laptops in the dustbin when it eventually stops holding charge.
I own a Lenovo X301, which is completely user serviceable. Lenovo publishes detailed DIY dissection manuals on their website. If you want to install Linux on your Lenovo, you can do it two ways. One, order a standard Lenovo laptop with Windows on it and buy a separate SSD. All you need to do is to remove the battery, remove one screw, and the SSD slides out. You can then install Linux on the other SSD and swap between them as you wish. And yes, instructions and drivers for Linux are available on Lenovo's website. The second way is to order a laptop preconfigured with Linux from Lenovo.*
I can not comment on the others (Dell, HP, Asus, Fujitsu, Sony, etc) except to say that Sony's and Toshiba's are far less DIY friendly than Lenovo. Neither Sony nor Toshiba publish DIY dissection manuals, and the drivers weren't readily available the last time I looked.
I would second Amir's suggestion that you avoid anything with radical hardware (e.g. touch screens) unless you want to run Windows 8.
* (edit) I just checked Lenovo's website. Some models can not be ordered with Linux. Regardless, nearly all laptops in the PC world have easily replaceable SSD's. Just make sure that Linux drivers are available before buying.
