The sniper buffs so far:
- masscost = 640 mass (from 800); buildtime = 3600 (from 4800)
- speed = 4 (from 3)
- + 100 HP for Aeon sniper (550 from 450)
- deploy animation removed for Aeon (but not charge delay) and locked turret removed for Sera
- t1 units are removed from their target priority, so that they don't waste shots on t1 units as soon as a t1 unit enters in their firing range, unless manually told to do so
So they recieved several buffs and, they really need to be buffed but I'm not sure all are necessary. For me, the most important one is cost reduction, second most important is the suppression of deploy buggy animation and possibility to shoot on the move by unlocking the turret, so that they can aim, and prepare their shot while moving.
I don't mind the small HP increase considering they still cost a lot of mass that is higher than their total hp, though I don't understand why Sera sniper didn't get any HP buff.
However, I mind the big speed buff of 4 (from 3) because on flat maps where there is lot of space, like Open Palms, it's gonna be really hard to chase them down with anything but air units.
Furthermore, for Sera snipers, they have a second firing mode, that deals huge damage at the cost of speed. They used to be quite slow in this mode (2.25 speed instead of 3). They will be as fast as their previous default speed (3) while on that mode.
It was found out that they ignore t1 radar blips because of the removal of t1 units from their target priority list. I see that it is a problem indeed, so this change can probably be removed (it's a pity though, it's very easy to send a mixed army with t1 units first that will make the snipers waste shots, wether they are in radar range or visual range).
Finally, about their accuracy while shooting on the move. It's not because they can shoot on the move that they always hit. Their shot doesn't home, and if the target moves, and the sniper moves too, there is a good chance that the shot will be wasted at long range. However, if it seems they are too acurate while on the move, there is a function that can be added that adds randomness to their shots on the move ( FiringRandomnessWhileMoving = x,). With a very small inaccuracy while on the move (it has to be really small, like 0.1 or 0.2, because the faster the projectile, the higher inacuracy gets), it'll be harder to kite with them, but they will still be able to shoot in the proper direction and hit shields or big targets for instance.
That being said, I'm really not sure it's necessary. I watched a replay where Lu Xun used snipers, but they didn't seem to be too easy to use nor too powerful (he moved on producing Aeon SCU instead).