It changes the way you play... deal with it.
Ask those Mercs who got smashed back in 1.2 because of PvP.
It happens. Your range has changed. That's not that big of a deal, it just means adjusting to the difference and moving on... I play a PvE vanguard. It's NOT THAT BAD.
It changed it to the point where IMHO I think Tactics beats Assault. Running countless parses comparing the two along with real world tests (wzs, fps), they produce around the same DPS (albeit, Assault is more RNG based and can at times out perform or under perform, yet the averages still even out). So, with that in mind, the extra mobility (constant +15% and +30% on demand with 30s CD) with the 30% reduction in AOE damage and while stunned, along with a shorter interrupt, gives Tactics the edge in PVE/PVP (more so for PVP, especially with shorter CD on harpoon). This is just my opinion of course. Believe me, after running Assault for about 6 months now I'm heavily baised in favor of it, but will do what's best for performance and at this point I think that means dropping Assault for PVE/PVP and running a Tactics build instead.