Well everyone is talking that a "pulse discharger" is better for these IB packs, especially for the 4200SHV's and 4200WC's.
So..
Much More CTX-D2
Trinity Dyna Pro Discharger
Team Wave Lightning 2
Spintec does have a Version 2 discharger coming out, but thats for the hole pack where teh ones listed above will prolly be better.
All I know as of now. Im going with the DPD personally.
But people are still doing the traditional 20-30 amp bulb discharge, then putting the packs on some type of tray, Mostly a smart tray which is great, I had one.