Has anyone used the Happ's 1.5" trackball?

[bigdruid]

I've got a JAMMA cab, that already has two joysticks and 8 buttons (not counting the 1P/2P start buttons). As you can imagine, I don't have much room left on the control panel, and I want to add a spinner and a trackball so I can play some games with MAME.

There are a couple of really small spinners that I can fit on my CP with no problem (SlikStik Tornado and Oscar's Model 3). The problem is that the 2 1/4" trackballs are *way* too big to fit in my CP.

It looks like I just barely have enough room to put a 1 1/2" trackball in there (http://www.happcontrols.com/trackballs/56020000.htm), but has anyone ever used one of these smaller trackballs? Are they speedy enough for games like Marble Madness, but still accurate enough for games like Centipede? It is *NOT CHEAP* ($142), so I don't want to blow a bunch of money on it if it's really too small for arcade use...

-druid