it's great stuff, i think. i first used it to spray the underside of the hood and liked it so much that i decided to use it in the bay. it leaves a slightly fine texture and dries pretty hard after an hour or so (maybe less). i had to touch up a couple areas because i didn't wait long enough to put stuff back in.
i took out all i could (cai, etc) and degreased/pressure washed the bay (covering all electronics). after letting it dry completely i masked stuff off and started spraying--didn't even scuff anything.
i got the more expensive one @ Advance--it's about $8 a can and i used almost 2 cans.
for about $16, i'm incredibly happy w/ the results. i'll post some "before" shots--HELL of a difference!
that undercoating stuff is horrible... tried it on some other stuff and didn't like it at all.