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.
Against my will i shelved my vanguard...
I changed my other trooper, a combat medic commando to a gunnery DPS and even using a rifle i can output as much as or even more dps than my old assault vanguard.
The guild i'm part of is in the need for ranged DPS for our raids and ops and i was doing well until the assault vanguard was nerfed. Now even if i switch to tactics, it won't serve me anymore.
This last weekend we ran a 16 men Eternity Vault OP and if i was using my vanguard, due to the melee range, i would've died countless times, even using protection CDs and with the good healers we have.
Even the Ops leader told us to avoid staying in melee range as much as we could.
As a gunnery commando, i could keep myself within the 15 ~ 20 meters range and do A LOT of damage.