on a very personal point of view....working or not??? performance or whatever....controlling a spin (I think) can be really great.

I did make a spin...just for fun..of course the thing wasnt control-able...but it was ton of fun....anyway....it looks great....(and NO I will not post a pic....someone might call me "hostile" again LOL )...lets just say that it was some "special" design...I guess you see what I mean
Last but not least:

Lets not forget the fun factor!

But; for sure on a J...the thing could work great....I really hope; that one day it will become available (did I just say that???)...