Does anyone make use of these things? I've bought a few indoor plastic balls to play around with. I'm really liking the readers indoor balls, I'm hoping that I can practice with them outside in the winter in damp weather. They seem to behave pretty much like a normal ball, good feel, but when I bowl with them they often fly down the legside, bit like a drag down. I am actually wondering if it would be good technical practice to master bowling with these. I think I could bowl legspin pretty much all day with these and not trouble the shoulder. I've found the 'supaball' to be really good for indoor (i.e. in the house) hand-to-hand practice, has a nice seam and feel but it's unlikely to break anything I've tried a windball too, but not sure these are so useful.