As an Infantry Lasgun enjoyer, this hurts so much. Currently the best lasgun is the Heavy Laspistol.
Lasgun’s only purpose is deadly accurate blessing for a crit build, other than that using it is a detriment.
Or headshots build on vet
even the normal las pistol seems to be very good
especially after the buff it got
las pistols being good than the lasguns 
Deadly Accurate implies going for headshots, so yes, my go to build is no keystone crit headshot veteran build with DA + Ghost or HH.
Accatran is currently flogging Kantrael in the Las weapons department, obviously.
Kantrael Las Pistol can hit some fun break points on Marksmen Focus Vet, and Desperado blessing has helped it’s reliability a ton, but it does still heavily lose out to accatran unfortunately. Still more fun that it was when it launched.