Is this something that everyone's using as a norm?

No. Default has it off. And if you turn it on without a proper backlash solution on your Z axis, you have a good chance of seeing quality problems. Then again, it wouldnt hurt to try it either.

Keeps from messing up the surface of the print. Slic3r can do it, it's called z-lift.

Actually, it should probably be called "Z-Drop" :-)  Never noticed it...Thanks!  I'll try it out on my next print.  Is this something that everyone's using as a norm?

Their stuff is $200/kg of filament And for some silly reason it always leaves 50ft of filament in the cartridge (grrrrr.)

I have to appreciate that they have a lot of patents and development work that is good, even as I jokingly tease.

It's not just the surface of the print, it's also so you don't knock down thin columns.

Our school's printer just uses PLA as the dis-solvable support (in mild NaOH with ultrasonic cleaner), which makes me wonder why more at-home printers haven't been doing PLA as dissolvable with cheap chinese ultrasonic cleaners. PVA is better for dissolving, but for some reason more expensive to produce.

While it was running I noticed that during every non-extruding move, the z-axis dropped down about .5mm and then rose quickly back up to continue an extruding move.  They have obviously programmed this for a reason, but frankly I cannot think of why that would be important.

Any insights?  Just curious...