You can easily wipe the BIOS.

Sure, but it's unlikely a thief would.

That doesn't seem very practical.

It is if you make a habit of leaving your laptop laying around unlocked and enjoy writing blog posts to that effect.

Oh, but for actually using the computer? Yeah, somewhat impractical.

(My worry is not the $1000 I sunk on an easily-replaceable chunk of plastic wrapped around my data. It's my data. So my laptop boots up to "type the encryption key", and if you don't know it, you have to erase the disk and install your own OS, keeping my data safe. I'd rather my private data stay private than to take a picture of someone stealing my laptop. Also, my laptop never gets stolen.)

It's pretty easy to wipe lojack from your laptop BIOS... I did it a few times before.

sure, but how many people would even think to wipe the OS or replace the hdd because of something like prey or lojack, let alone wipe the bios?