I'm not sure what type of terrain you were on when you "floored" it and still weren't satisfied. I've been all over the west (Sierras, Rockies, Cascades) and have never had trouble climbing over anything I've pointed my truck at. As a matter of fact, I don't think I have ever actually floored...
Well, I haven't had the BFGs long enough for a full report on longevity but they most definitely are much quieter than the Duratracs were when they were brand new. And the BFGs are 285s (vs 265 Duratracs). I actually cannot hear them at all unless I'm out of the city (ambient noise) with the...
I can relate as I just just came from a set of Duratracs (LT265/70). I had 36K miles on them and they were loud, never quite balanced, and didn't track very straight at highway speeds (required a lot of input). Went off-roading a month ago and opened up the sidewall on a very routine hill...
I don't know trail ratings but if I were to rate it on a 1 - 10 (10 being most difficult) scale, I'd give it a 6. It also depends on which route you take (side trails). I did it alone with no problems.
It's pretty easy except for a few somewhat challenging parts. You'll be fine with your setup. Most of the challenging stuff is on the side trails and they usually have some sort of bypass if you're not wanting a challenge. No extra fuel needed. The trail isn't that long. Have fun!
It's this route:
If you're coming from the town of Idyllwild, you'll make a left onto McGovern Rd. just outside of town (33 45'43 N, 116 44'15 W).
The trail is scenic and has a few somewhat challenging sections on some of the off-shoot trails. Enjoy. :)