I got to play around with one for a while and it felt really good. The cue feels a little heavier, but the weight is distributed in such a way that it doesn't feel heavy. Not much of an adjustment to get used to it and it's already come in handy on a couple of shots that I had to stretch out for. No problem reaching and shooting. I measured it at 1.9oz, which brings my cue to 20.7. I really like it and I have been getting lots of looks and comments in the pool room.
Here are couple pictures and measurements with Balance rite Extension, also you can find how that extension fit with Joss J69 butt and Joss standard shaft, Predator Z2 shaft and Mezz Deep Impact shaft.
The extension that I received has:
Length: 103 mm (4.055 inch)
Diameter: 215 mm (8.465 inch)
Weight: 60 gr (2.1164oz)
Pin: 5/16 x 14