Yeah, I'd be real interested in the experiences with grandpa. One could argue that grandpa shouldn't be driving if he won't do the posted limit....
That said, it wouldn't be a problem if grandpa got out of the way and let traffic flow. The real beef I have with this is that there are the hot-heads that start acting very aggressive when they are stuck behind the slow poke. Yeah, at the root of it the hot head is at fault, but the slow poke is a significant contributor. My goal is to not be killed by the hot head, so both people bother me.
The traffic camera I'd love to see is the one that will ticket someone driving slow in the left lane. Put them in the whole length of I-5 and start collecting the $$$$.