I've never driven previous generations off-road, but my 4th Gen. is very capable. In terms of off-roading mods, I only have Terra Grappler Tires and a 2.5" lift, but at a recent run in the snow, I was the only 4Runner that never needed the assistance of a tow strap:
http://www.toyota-4runner.org/showth...threadid=14984
If the course was more technical I'm sure I would have needed help too, but as described by my fellow off-roaders that day, I "walked" over all the obstacles without any problems.