My experience with the German line:

So ive been playing the game on and off since the beta but i only semi recently started to try and make the horrible grind towards the T10's, of which i got the E100 and the JgPz-E100 (i say grind since the only time ive ever spent money on the game was to buy a Lowe to make money with).

My experience with these tanks has so far been thus:

Lowe: Pinpoint gun and with a supercrew and right equipment can get the reload time to 9.43 seconds, so not much slower firing than a Tiger 1. The turret armor can deflect mostly everything up to t9 and even t10 occasionally. Sidescraping is a bit trickier since in my experience it can still get penned relatively easily, but by only exposing the turret you're good to go. A bit slow on upwards climbs but it can get there when it matters. Overall, a great tank that can still tackle most other tanks of its tier and can sometimes tackle bigger ones(except the bullshit that is the BZ-176, burn in hell WG for putting that OP in the game).

E-100: Crap. Oh so crap. A Maus it is not, that's for sure. When playing with t10 you have to accept the fact that you'll need to play with prem shells, but to get 12 seconds of inaction with a gun that cant hit anything after you take 10 steps away and will mostly bounce unless you aim at a tank's weak point (which you might not even hit due to the aformentioned dispersion rate) means you will simply be there to hold flanks and rarely poke and shoot. Worse, since most players play gold at t10, that flimsy turret you have will 100% get pierced no matter what. HOWEVER, if you do get god tier RNG and get a fight vs t8/9, you are set. You will be able to mostly waltz right in no matter where or when you want, as long as you got a couple of people behind you to exploit the push. Overall, its one of the weakest T10's ive seen thus far if we speak heavies, and i wish i could get a Maus for it instead, since at least Maus can deflect stuff a lot more.

JgPzE-100: This one is… strange. Slow as molasses, super accurate gun and of course i have to mention 420 derpetration shells. I love this tank, because it removes the worst part of WOT for me: "I shot the fucker in the weakspot and it BOUNCED?". The armor is not that impressive for its tier but you can still occasionally bounce a few long shots here and there. Because of the huge frame sidescraping is not truly possible as you will be exposing your front by the time you can take a shot and the lower plate can still get megapenned easily. Its not really a sniper due to the slow shell speed but if you hit something (as long as you dont track it by accident), you will 99% of the time pen it. Ive pulled off miracle shots with this thing but of course the 20 second reload time is a bitch and a half to deal with, even with the right equipment. Overall, as long as you dont go off alone to fight the enemy, as a support tank and even a slow poker this thing can turn a flank into a flat.