If it was me i would stick with the 6pt. The 6pt offers a greater contact area, also less rounding and stripping bolt fasteners.
The only 12 points I own are sizes commonly used with 12 point fasteners.
certain things require a 12 pt, I know of a lot of ARP studs that use 12pt nuts on the studs, and you need impact sockets most of the time to take them apart and torque them back down. I have 3/8" and 1/2" 12pt impact sockets as well as 6pt sockets. guess it depends on how much you work on different things. the last 6L diesel I did I snapped a snap-on 13/16 12 pt 1/2" drive impact socket taking heads off that had warped. had it replaced and torqued the new heads back down 210 Ft-Lbs...
Random question, are 12pt or 6pt sockets cheaper to make?