I don't do this regularly, i've done it just to check it out.

When mining x-11 on my i7 3632qm,  I get roughly 20khs a thread
When mining x-11 on whatever cpu is in the other laptop I tried it on I get roughly 20 khs a thread (I've left this one on for days and the laptop didn't blow up, but I don't care if it does, as i'm assuming you don't)

People seem to be getting more (i'm probably doing something wrong), there is probably much more efficient coins to mine (bytecoin threads seem to always pop up), but do you want to change the pool on 25 computers every day, or just leave it on something more stable.

I'd do it for the hell of it since you have free power.