Actually I use them regularly and if I do say so myself to rather good use.
Here's the replay review I got today with my E8s.
https://www.coh2.org/topic/69692/usf-and-okw-1v1-review-please-requesting-dave-j4j-or-devm
I don't expect my E8s to deal massive damage to infantry. That's probably why I find them good. I expect the HE sherman to do that, and I expect the E8 with its 215 armor, 720 HP, decent pen and good mobility (0.75 moving accuracy debuff) to deal with armor.
However I'm sure the unit differs drastically from 1v1 to 2v2. In 2v2 you have to worry about the StuG from ostheer coupled with pak walls and raks etc. But in 1v1 for its fuel price it can 1v1 either P4 easily due to its 5 shot kill HP pool.
this dismissive attitude toward 2v2+ is why the balance swing so heavily into team game.
the Ez8 is a good tank if you don't have to worry about t4. It will easily out muscle the pz4 and maybe even the stug in a head on contest.
However, while the armor, gun, and hp package are all decent, its mobility is mediocre for a medium tank. At 6.1 2.1 it's slower than the wehr panzer 4 (6.3 2.1).
Once the axis are able to bring their stronger armor into play, the ez8 will find itself outmatch in both speed and brawling capability.
It's too slow to be an effective flanker and too weak to brawler against the heavy. The 76mm have a weak HE and its mg is pretty weak as well. The panther is both stronger and faster, and now with the new mg the panther is almost the equal of the ez8 at killing infantry.
Medium tanks are more than just about killing tanks or some hypothetical 2 medium vs 1 panther match. Exploiting gaps and killing infantry are just as important if not more so. In this job the medium tanks keep to keep itself alive to justify the cost.
It's like not tank destroyer or heavy tank where they can reliably kill other high value target.