While I have never visually seen the Rubicon Trail, I have walked a good part of the Fordyce Creek Trail while I was camping up there last summer. There were several spots that looked like no problem, there were also several spots that looked really tough. Most of the rigs running this trail were full on rock crawlers and way lifted Jeepers. Next time you and Linda get out here be sure to let me know, we can at very least get together for some brew and food if not wheeling. This area is only about 45 minutes from where I live.
Bart