I got my modded B/K and R/C back from Chris Neff yesterday. Woo-hoo! Thanks, Chris!
I played with them a lot at juggling club today, and really do notice a marked difference, compared to the as-purchased tops.
The increased spin time and stability are the most noticeable improvements. The improved weight distribution due to the mods must be the reason. I also really like the custom-made strings Chris provided.
All in all, WELL worth the money spent. Thanks again, Chris....