Hi Bob:

The UP-6 is a great little valve. It does not use air like my electronic Graupner's do in the propo mode. It is more like the Smooth Stop. I have used them on my Roo and HotSpots before I switched to electronics, but also use the Smooth Stop on my Bandit.

The only downside is that it is spring loaded. It puts quite a load on a microservo like the 341, so I end up going to an intermediate size servo. This just takes up more room---not a big deal.
On my electronics, I don't use the air-guzzling propo mode, but have my on-off brake switch on my snap roll button on the 10X, and then use the right slider for extended brakes-on if I need them. By tapping the snap roll button on/off about 2x/second, you get a proportional effect with no brake locking using either Glennis or BVM brakes.

Tom