Prepare for the most nit picky post i've ever done. Basically while functionally it's the same as in it's 3 shots and somewhat resembles the CE pistol there are quite a few different things about it.
The original CE pistol was not hit scan. This one is.
The original CE pistol did not have a yellow laser sight on the side.
The gun model itself differs. Both the anniversary and the OG one look slimmer and less blocky. Basically it looks bigger for seemingly no reason.
The melee sound, pistol flipping from the melee, and gunshots are not the same.
The swap to, reload, and melee animations are all noticeably quicker.
More bullet magnetism as well.
They did get a lot right though. it looks close enough to the pistol. it is a 3SK. The spin death animation is there if you land a headshot as the final blow etc. And I also realize it being a power weapon in warzone requires a bit of changes to it to make it well...a power weapon.
What bothers me though is that the halo 2 BR they brought in is more accurate to the OG 2BR then this CE pistol is to it's OG form. and the advantages it gets for being a REQ make sense. faster swap times for the noob combo, faster melee recovery for the BXR throwback. faster reload times and tighter spread coupled with the drastic increase to bullet magnetism. etc. Really the only thing that's off about it is the looks. But that's because they pulled the model from the anniversary of 2.
I guess i'm just a bit more miffed because CE is my favorite halo to this day. and while it's cool to have the god gun back this really doesn't feel like the same weapon outside the 3SK.
EDIT: I guess I should clarify. What I was referring to as far as the gunshot noises I was referring to hearing it in 3rd person. In first person it sounds the way it should. The melee sound and flipping is still off though.