There are a number of tanks, the most obvious of which is the T-54 with the D-10T2S gun, which rely heavily on premium ammo. In the live version of the game, these tanks/guns are balanced assuming liberal usage of premium ammo.
With the "New Balance" changes nerfing the relative damage out of premium ammo vs. standard, that means tanks that currently rely very little on premium ammo are getting a substantial buff (Leopard 1, most TDs, etc), and some of those also have strong armor, so they're getting doubly buffed (Obj 277).
I haven't seen any information yet about penetration values for standard ammo. Has WG mentioned that at all? If they just go live with this "final" round of testing from the sandbox, it's going to be the biggest fuckup in game balance since those auto-bounce angles I heard about several years ago that made some paper tanks impenetrable.
Source: https://www.reddit.com/r/WorldofTanks/comments/f1we2w/sandboxnb_no_standard_pen_changes/
