Depends. I have a X41, which gets flakey with the headphone jack when you put the laptop to sleep (requires a reboot to get it working again). Other than that, I can't remember having any issues with it.

One of the nice things about it was that the volume / brightness hotkeys were hooked into the BIOS so I could use them even when the OS was locked. I believe all ThinkPads are like this. I miss this on my current laptop.