KV is very good, KV3 is good, IS sucks...but the 122 makes it much better.
I hear good things about IS3-IS7.
I liked the KV ok. The 107mm gun makes it nontrivial even in high tier matches. But you die real fast & you're too slow to get away from anything. Same goes for the KV-3, but it's even slower; as if that were possible. Both tanks are monters in their on tier but I find the lack of speed extremely irritating in higher tiers.
A similar statement can be made of a lot of the low tier french tanks... like AMX 40: super rape in tier4. Unbearably slow/vulnerable anywhere else. But its worse here b/c your gun has no significance in higher tiers.
The IS doesn't suck. You need the 122 and you need to learn how to use it. The tank is a peak a boo tank like most of the russian ones. You keep in cover, pop out and hit something with your big gun. You hide while it reloads.
The IS3 is a lot better now that the sloped armor changes were made.
I'm not sure what you're doing or how you're playing but the Tiger H is food. Any tank I'm in they are free kills. That shitty flat armor deflects nothing. Hell I eat them up in Chaffees. The Tiger H in this game is just sad.
I don't have the 2nd 122 yet (nor the turret). With the 100mm, I think you'd agree that the IS is not a brawler. The alpha damage is terrible. And you rarely bounce shots from same/higher tier opponents, so peekaboo'ing with the 100 is fail. But as above, IS is quite strong if it gets top tank. So far I've been told to play it like a medium which is what I've been doing.. and eh. T-34/85 gets the same 100mm gun. But again my tank isn't maxed yet.
The Tiger H is awesome. Maxed, it has the same power/weight ratio as a maxed IS. So it feels very agile (well the reverse speed makes me cry). 203mm of penetration is significant even in tier10. 175... meh. And the accuracy means I can bitchslap anyone from anywhere. With it's large HP pool, I feel comfortable going head to head with any other tier7 tank. Yeah maybe my armor sucks & they'll pen me, but with the long88 I'll pen them all the time too. But I prefer to stay in the 2nd line, providing support fire--damage, tracking, etc. It's easily my favorite tier7 heavy.
I guess fundamentally I like high penetration, accurate guns: sniping FTW. And I'd trade armor for mobility (not straight speed but agility) unless my armor is so awesome that large numbers of enemies that I face will bounce. That choice is mainly due to having to fight higher tiers. When you're bottom, your armor will get pen'd by anything but your speed never goes away.
yea everyone will tell you the 122 is the way to go on the IS. however i completed my grind using the 100mm, fast reload, way cheaper ammo price, pen isn't that much less than the 122. it just felt like i was able to do more as i play pretty aggressively, as opposed to peak and hide.
I find it hard to be really aggressive w/this tank (except when you're top). You don't move around particularly quickly and the side armor is easily pen'd by anything tier6 and many things tier5. I imagine the agility will get better w/the last engine but right now it bears little similarity to a medium. T-34/85 gets the same gun and it feels way more powerful in that setting.
I had mixed feelings with the 122 on the KV-3. I tried both 100mm and 122mm there (they both pen 175mm btw). The alpha damage was pretty sweet at times but the long reload sucks. And missing/bouncing sucked. I think I made less money with the 122 on KV-3, but bitchslapping a KT for 450 damage feels GOOD, haha.