As someone who has both the ipv4 and ipv3 li, I prefer the ipv3 li other than that there are currently no silicone sleeves designed for it or its predecessor ipv3, which leaves the mod slippery and unprotected. Picked up a jwrap for it, so once that comes it should be better. Love the solid build and metal casing, feels better-built than the all-plastic ipv4.
-Treeburner
IPV3 Li Silicone Case - Pioneer4You - Electronic Mods
I just ordered the IPV3 Li and have been googling for a case, besides alibaba this is what I could find.