Recently I put together a 49way joystick that features an illuminated balltop and I have been tossing around the idea of offering the same thing to the community.  What I am trying to find out is how much interest there would be in something like that.  A ballpark estimate on price would be in the $50-$60 price range.
I'll try to get some pictures taken and posted this week.  Currently I am using the Seimitsu LB-39 "bubbletops".  They look pretty good and they do a good job of dispersing the light, I just wish they were a little bigger.  I thought about using the transluscent versaballs, but I don't know how well they would disperse the light and I also haven't been able to get an answer from RandyT on whether he would sell just the ball or not.  I didn't see it as option on the website either.  Another option was to get my own made but I am hesitant to do that for right now.
As far as the feel of the joystick, I personally like it better than the original but that is something that is going to be personal preference.  
As far as durability, the joystick is made from 90% happ parts and seems to be rock solid.  I have had 2 installed on a cabinet for 3 months and there hasn't been any problems.
I'll do my best to answer any questions that anybody has and I'll try to get some pictures posted asap.