Wendell SF...it's not fast and it's flow is a little harder to appreciate, but it is part of PV heavy hitters and a must visit IMHO!

I just did a grand tour of Charlemont Trails (Warfield House, Zoar and Berkshire East)---very excellent trail system, climbing is extensive, but so are the descents. Also very worth the trip.

The Kenneth Dubuque SF is worth visiting as well....all of these places work best with a local guide...

Hare, I am surprised you didn't mention Robinson SF in along side Earl's (after, that is probably the fastest and the flowiest park in the PV).