I agree to 100% with necrons. One could never rely on the chiefs armor. Even hullown it is not that hard to kill it with aphe. With the apfsds buff there are cheap rounds ingame that can even pen the ufp at 70+° and go through the turret virtually everywhere. Im actually pretty certain the turret armor is modelled not properly and the gunner/commander side has some artificial weakspots in the sub 200mm area it should not have. I had some hope theyd refine the armormodell once the add the mk 5 but they diddnt. Same goes for tbe lower part of the ufp. Unfortunately i have no sources for that but it seem just wrong to me.
The apds... Yeah every minor patch i read the notes then i do a testdrive and shoot a is4 frontplate and then im sad. Even a slightly angeled t-54-47 is a hard nut to crack at distance now - a medium a whole br lower. The chief may have the biggest gun of the top br mbts but is ironically the least potent. You learn to appreciate the reaload tho, especially after a few matches with the t-62.
Once spaded the mobility gets a lot better but until you get there.. boy... I would really like to know why especially the chieft turns that bad ingame. I mean this ads nothing to balance it it just pisses of its players.
Still it is somehow my favourite t5 tank and i cant really tell why..