And which slow it down second most?
Looking at Nivlac's very handy guide for everything equipment it seems this info is missing from the excel sheet.
http://spreadsheets.google.com/pub?key=rlERT2XT_6dXpQSXJ1ir31Q&single=true&gid=3&output=html
TIA
I may be wrong, but I believe the GI-SD balls slow the swing down to the same degree. At least that's how they are rated in the pro shop. And they have more spin and more distance. However, I may be missing something...
Updated the balls section of the charts. The GI2 series balls (S or D) slow the meter down the most with a 4 of 10 feel rating. First-gen GI balls are only 2 of 10.
IMO, the best non-pro ball is the GI2-S because of the extra durability.
Thanks everyone for the help.