Just got mine hooked up to the frankenpanel I use for testing, so let me be the first to review!

Well, it's certainly easy to mount. Just remove the knob and put the shaft thru any 3/8" or larger hole.
I ordered this one with the DOT knob, so this is the first time I've used this type of knob in over 20 years. For the record, if you're using a Mini-Pac, you have to break off the two outside plastic tabs behind the header pins for the spinner harness to fit. I also had to reverse the x-axis in MAME with the Mini-PAC.
That said, Oscar's sensitivity settings are bang on! I tried a setting of 50 for Tempest, and it does indeed give you 3 slots/180 degree turn. I found the size and weight of the DOT knob very nice for Tempest. The Push-action is firm enough that you will not accidentally hit it, you definitely have to concsiously push it. I rather liked the effect of setting the Super Zapper to use the push-switch, so I could just concentrate on firing with one button, and slap the knob when I was in trouble. Very cool.

I had to try Forgotten Worlds, which I've had on my machine for some time, but have never played. Definitely an interesting game. I had to crank my sensitivity all the way to 255 to get any decent response time out of the spinner, but once that was done, I was doing pretty good. It is a little bit difficult to manage all the turning and shooting since the knob is the ONLY fire button in the game, but once you get accustomed to it, it works pretty well.
Overall, the spinner has a nice feeling. It truly is compact, taking less space on the panel than a regular joystick. The spin is slightly noisier than the Vortex spinner, and it spins slightly fewer rotations-per-crank than its forefather (V2 spins 3-4 times, while the Vortex spins 5-6 times) The spin time is more than enough than you would need for any game, but if you like 3 minute spin times, you know where to go...
The extra space between the plate where the shaft bearing is, and the underside of the CP seems to leave open possibilities for some kind of lighting kit, but I'll be happy just to get a pull-kit on this puppy!
All in all, a really nice spinner for the $$. My spinner has a first name, it's O-S-C-A-R, my spinner has a second name, it's...uh...
...O-S-C-A-R!