Little late to this thread, but I've played with 3 different groups that rented the ice. 2 of them for certain did not charge the goalies, I think the third may have.
I want to have goalies in both nets personally. No, it's not a league game or anything, but the whole dynamic is completely changed. When you're playing posts(sometimes we'll hang a sweater on the crossbar), once a guy's 10 feet inside the blueline, he's looking to shoot. Unless there is a defender right on him, he's not passing. There is no play behind the net(which is kind of where I'm usually a little more effective, so I am a bit biased), and the other team isn't really defending, they are just hoping to make you miss with your shot. You're not trying to set anything up, or work the puck to the point, just trying to get a shot and then skating back the other way. There's never a sustained time of holding the puck in the zone.
You really are only playing somewhat normal hockey in 2 of the three zones. You can break a sweat, yes, but..it's much better when both nets are occupied.