I used to love this tank on pc when i started playing wot, i had it on my xbox 360 days as well, so i decided to get it on ps4 too.
Well i'm gonna say that i regret spending hours of playtime and silver to get it, as it's just not a competetive tier 10 anymore. In theory it's a very well balanced jack of all trades, in practice it doesn't have a place in the meta and i will explain why i think so.
On pc, even before the HD model update it used to be go to tank for all the players that liked the idea of having a very mobile heavy tank with a relatively sleek profile (except for the gigantic turret on top) and semi-reliable hull armor for city maps, something that the Patton couldn't even dream of doing back then, being a huge paper armored target. However the biggest deal breaker that made it unplayable was that even tier 7/8 standard rounds could pen it reliably aiming at the LFP and the top turret, which made it pretty pointless when playing against competent players.
Later on they gave it a massive armor buff with its HD model, making both the LFP and top turret (most of it anyway) almost impenetrable to even tier 10 premium rounds, more than 50% of the time; and so they nerfed it: made the LFP a very reasonable weakspot that even tier 8 tanks can use with some careful aiming (as it should be IMO, tanks NEED weakspots) and nerfed the top turret again to a middleground between hyper buffed and original paper armor values. That also was fine because most tier 8 and 9 tanks would have to use premium rounds to hope for a 100% pen rate and tier 10s would have a pretty fair chance (i'd say about 70%) of penning with standard ammo at normal ranges, which is fair considering it's way too easy to hit and there's no way for an E5 driver to hide it completely even in a sidescrape. Sure, HEAT spam would send you back to the garage in just a couple of minutes considering the low HP pool, but it still was the best tank to act as both an occasional frontline brawler, a dpm machine and an improptu medium flanker: DPM was godlike, gun depression used to be quite a unique feature amongst tier 10 heavies and mobility was pretty much top tier, you traded armor for all that.
A few patches and years later it's become pointless: Super Conq is pretty much what the E5 strives to be, except it does everything better (much better) and has some of the Best frontal armor in the game, with no apparent tradeoff (i guess the E5 does have 3/4 kph top speed advantage lol), the Chieftain, 5A and 277 all do a better job of playing the medium on steroids role, while also having reliable turrets. Finally the updated M48 is just a better pick if you're into american jack of trades type of tanks.
So why keep playing the E5 when you could get one of those and get better results? Honestly i don't have an answer, i guess i'll keep playing it because i have a soft spot for it and that's it.
As for how i would fix it: 9/10 deg of gun depression and lower profile tumor on the top, same armor values. Hell i could even accept a moderate armor nerf if they made it as hard to hit as it is on the updated M48.
Sorry for long text, but i feel like i would get dismissed if i didn't explain my reasoning.