I also would go for Stonyford ... or how about the Shasta Dam area (I forget the name). Nice to see some new trails and some of us could ride share from Oregon. I am open to other ideas too.
I have always wanted to hit those as well.
The Chappie-Shasta trails are really neat. I first rode there about 10 years ago with the guy that used to be the Enduro Steward for the Redding Dirt Riders club. He laid out all the courses for the Buckhorn Enduro. It was April and there was howling snow up top and very warm temps down low. We saw some pretty amazing stuff, most of it unmarked. The BLM/USFS has done a pretty good job of marking stuff since then and there are actual trail maps available now. The problem with that area is it has a very narrow window for decent conditions. There's a little bit of snow in winter and the wet mud is pretty slick there. It seems to go from too wet to blazing hot in no time. It's no fun in the high heat and dust. It would be good for a spring ride next year, or maybe even a fall ride this year but it's hard to get good conditions when planning far ahead for a group ride. That's what bit me in the butt for the Stonyford ride. It was a real shame there were hardly any riders to enjoy what Stonyford had to offer...