Regarding "speed" i think we can fix that by adding a charging mechanic.
Give the PPC two modes of opperation.
Regualar mode - hit FIRE and let go:
- PPC fires as usual; chain-fire possible.
- the Particle Projectile" flies at regular speed
Advanced mode - hold FIRE and let go to fire:
- PPC will charge and fire as soon as you let go. If you hold to long the gun will simply discharge (same mechanism as the Gauss here); chain-fire impossible. If you want to fire more then one PPC you have to link them.
- due to the optimized charging-process the Particle Projectile will be fired at a much higher speed (at least the old, pre-nerf speed, but i think 3x the current speed could also work).
(Note that using he Advanced Firing-mode requires more skill and patience, while in return your crosshair did not have to lead your target as much as in the current mode.)
I suggest this kind of mode to be used for all types of PPC, ER- and Standard.
(I think technically it would be more logical to use the Advanced firing mode only for the ER-PPC, as the charging process i described could in this case be explained as a necessity in order to create a stable Projectile which both lasts longer and has no minimal range.
Just a thought... .)
If it is impossible to use both modes in the game at once (say, for Lag-reasosn or what ever), let the players decide which mode the want to use; allow them to toggle between the 2 modes in the option menu, just like that for arms lock etc.-
Conclussion:
So, who ever wants to shoot the PPC like today can still do that - nothing changes for them - while others who want to have faster Particle-Projectiles will need to be more patient.
Lore / Canon:
Also: charging a PPC, with the gun slowly starting to glow in light blue before it fires, is also described in the novels pretty much in that way (i only have read like 6 of the novels years ago, and those were in German, so i have no idea if i was misguided, or if my memory is correct).
Plus it would look really, really cool (and possibly intimidating, as your opponent will see what you are about to do in a second).

Your oppinions, please ?