I have not used a Thinkpad for long enough to voice an opinion. However, MacBooks have very good keyboards. I think it's the best laptop keyboard I've ever used: no flex whatsoever.
Macbooks have pretty bad keyboards as far as I'm concerned. The horrible chicklet-style keys are just a pain to use, if you're not having the US layout, certain keys (Return!) get horribly small and PgUp/PgDown can only be activated using two keys. Please, this is not a keyboard, it's a toy.
I could understand this kind of decision on a really small keyboard for netbooks, but the Macbook's crippled layout is just a joke.
Thinkpad keyboards, while not perfect, are better. Newer models tend to have some problems with keyboard flexing, which is a shame, but I don't think it affects actual typing. Yes, the keyboard does flex, but you need quite some force to cause it to flex. It still looks ugly and cheap, though, so even if it doesn't affect typing, it should be remedied.
What I like about the Thinkpad's keyboard:
- grouped F-Keys
- Ins/Del/Home/End/PgUp/PdDown are grouped as well and remain as a block. This is just great when you are one of the few people who actually uses these keys.
- Fn is in a nice position, but opinions differ on that one
What I don't like:
- Half-sized cursor keys
- Esc in the wrong position
-huha