Batboard

Ran across a post that said something like "God help you if it's an R model". They were talking about parts. Anyway, I've got an XTS 3000R. What exactly does the R mean? How would that effect things if I opened it up? Thanks, I'm learning lots here.

The "R" means "ruggedized."
If your radio is truly and R, and not just a standard radio that's been put into an R case, then it's been sealed inside to keep out water and dust. The R radio chassis has a removable vacuum air extraction plug toward the bottom of the radio's chassis. The non-R radios don't have it.
All in all it's not an item to be unduly concerned about unless you're a member of a swiftboat rescue team or some similar activity.