berryman would be ideal for singlespeed or for packing in all your gear and camping trailside--that would be a worthwhile experience i think. i would go back, but not for a long weekend. it was epic for me cuz i was fat and out of shape, scared of hillbillies, and relatively new to mtn biking when i went there. it's many miles of scenic rolling singletrack, nothing too difficult except for the length of the trail. you need to carry plenty of water and food. i carried two camelbak bladders and a ton of food.
but if you've been to levis, don't go to berryman. you'll be disappointed. i prefer levis to syllamo but syllamo is definitely worthwhile. levis is more refined and polished. syllamo is rough--bring your full suspension or pugsley/mukluk/moonlander. i think syllamo would be a blast on my pugsley (if we shuttle up the mountain by car)