Bringing this thread back...
After my posts above, Chuck at Ball and Keg contacted me to discuss my comments and after some conversation he asked if I'd like to test out their new version (I'll call it gen 2 but it may well be a higher number). I happily accepted, agreeing to post a review after using it. I got it several months ago but didn't get to brewing and kegging a beer until mid February and finally have time to share my experience with the new version.
For starters, the new ball is smaller than the older version. It clears the keg opening with plenty of room to spare and more importantly it's solid and perfectly smooth. Although I didn't have an infection problem with the gen 1 version (used it in two different kegs) I had expressed concerns about the ability to sanitize it due to some roughness where they sealed the ball. This new one generates no such concern.
Next up they switched the magnets around and they're now polarized. It was easy enough to match my original capture magnet and mark it so now I can use either capture magnet with either version.
There is a different way to get the exterior indicator bead lined up with the ball inside the keg and to remove the capture magnet. Watch the video because it is totally different than the gen 1 method but I find it easier.
I thought I would have some difficulty getting the indicator bead on given that this time my keezer was full and I didn't have any room to maneuver the keg to find the float or even to move the capture magnet all the way around the keg to find the float. However I was easily able to find the float - maybe I just got lucky but I only had to place it in two spots and it locked on. A few weeks later I kicked a neighboring keg and while removing it I accidentally knocked the indicator bead off. I didn't feel like fishing that one out of the bottom of my keezer so I grabbed another bead (they provide several) and when I went to find the float again it locked on with the first try. Maybe I got lucky but it seems like this one is more easily attracted to the magnet than the gen 1 style. Maybe the smaller size equals less surface area and resistance and it moves more easily? Or I was just lucky.
So it's been in there for a while now and it works as advertised - it goes down as the keg empties and you have a visual on how much is left. It's pretty easy to setup - just watch the video one or two times. You do need to be careful about jostling or moving the keg or the bead will fall off but that's no different from the first version. My biggest concern about ease of sanitation has been eliminated. It's a simple and elegant solution at a reasonable price. I'll be buying two more so I can have one on each of my kegs.