I'm not sure of the weight difference, but I'm sure there is some. Does the extra weight of the tin top Samurai's make them more prone to rollovers off road?

They call it a tin top because it is "tinny" like a tin can, and light. The rollover thing is a myth created and made worse by consumer reports. In reality, they are about as stable as a Toyota 2wd truck. If it is lifted, it will raise the center of gravity, and you must drive accordingly. The tin top doesn't add enough weight to make a difference.

After building and wheeling both I would say the tintop does roll easier offroad but only slightly.  I have been over backwards and on both sides many times in my tintop in situations where my softtop wouldn't/didn't roll.  The same trail, same tires and suspension.  Just my 2 cents...  

The rollover thing is a myth created and made worse by consumer reports

Very true, Suzuki won there legal battle against Consumer Reports for their false reporting.  

On the other hand, if you DO happen to roll, actually having a little tin up there might help keep sticks, rocks, and other sharp objects out of your hair.

Thanks for the replies!  I think I'm going to Moab next weekend for my first trip out in it, and was trying to figure out which trails would be to much for it.