garmin760 does have a backup camera input, std plug and a HUGE list of campgrounds and RV services, dealers etc. Haven't checked mine specifically but it does seem to show good sam sites. It has a bigger list of campgrounds than any book I've seen, since it includes a huge number if not all FS, BLM, campgrounds and an extensive list of RV parks, State parks, fairgrounds etc. For me that extensive list is worth the admission price for the RV760. and when you click on a campground it often will give comprehensive additional info.
for campsites you can choose to selectively search based on a variety of critera you can check off, for example, electric, water, etc.
So far I'm impressed and happy with the 760. Just used it for a 2500 mile trip from oregon through idaho and montana and only had a few quibbles, that really aren't Garmins fault. For example one tunnel had a 10'6" side clearance and 12' ceiling clearance and garmin tried to reroute me due to clearance. BTW highway department website listed the clearance as 10'6", so can't really blame Garmin. I knew the road and knew there wasn't an issue.
Like anything, common sense must go along with using a GPS.