I haven't placed any caches. When I do place a few, I do plan on reviewing logs when they get full and comparing it to the online logs. I think in order for it to count you have to sign the log to prove you have been there.
I'm sure if I place a lot of caches log verification will become less of a priority but if I only have a handful of hidden caches, I figure why not. It's pretty simple, you either find it or you don't. If you do, sign the log. You gone through all the effort to find the thing.