I know this has been said and it will be said until they do this, but WarGaming. Please buff the IS6's penetration. You can't tell me the 175 base AP shell or even the 217 APCR rounds are good enough for today's WoT line up of O-Ho's, VK 100.01 (P), Defender, T26E5, even the IS-6 can't pen itself, at least if feels like it. The gold rounds are laughable at best when you start to face tier 9 tanks. They couldn't do anything to a E-75 from the front, they can't go though most of the WZ line. Its just wasting money that you could be using.
My suggestion is buff the AP and APCR rounds to a higher penetration, or switch to APCR stander with HEAT prem. The IS-6 was great when it was added back in 0.7.8 but it isn't that time any more. We have super heaves rolling around as early as tier 7, the same tier that that 175 mm of pen should work. And with the newest update coming out which not only is buffing all of the AT line but adding a new French line which will cause problems for anyone with low penetration like the IS-6. This isn't the same game when the tank was added, it needs to be updated to fit the game is in now. The amour in my case holds up pretty well, if you buff that, I'm not complaining. But please let the IS-6 shine again. That's all I would like. Other prem tanks like it, T34 for a example can take a hit, throw it back, and smack the enemy into the next map while the IS-6 looks at the enemy and tosses rocks at it. The rocks would do more damage then their AP shells.