I have both =p
PoT is a good sniper to have for PvE indeed. I am mostly a PvP player so that's what I think about.
You have an ability to go invis already in the perk tree and there is a helm that lets you keep raidar all the time with any weapon. I dunno, PoT seemed cool, but after I realize it takes like 5 seconds after ADS to turn invis, I stopped using it.