Use the 10.5 gun and HE shells on the hetzer
Yeah, the majority of the German TD line is great. The Hetzer used to be one of the original derp troll tanks, it still is but it's been nerfed recently. The Stug is great, the JgPz IV is a questionable tank but play it the same as the Stug and you'll like it. The JgPanther is nice and mobile but you still need to play it the same as the Stug and JgPz IV.
Then you get to the T8 choices: the Ferdinand is still one of my favourite tanks out there, though I sold it when I moved my crew to the JgPz E-100, it's still one of those tanks that people are wary of, even if you're facing tier 10s. The Ferdi playstyle is more sniper/ambush orientated and that continues with the rest of the line.
I haven't played the JgPanther II but it seems to be the same playstyle as the JPII.
The JagTiger... is a beast. Easily one of the best tanks I've played and I will keep it forever. It's the same offensive benefit as the E-75 but hurts more and I've found it to be more accurate.
The final TD in the line, the JgPz E-100, is another love/hate tank. If you have no issues using Premium ammo you will love the tank. If you don't use it, be prepared for some seriously frustrating games.
The trend with the high-tier TDs is that they have huge alpha but long reloads. However, if you get a bounce or a zero-damage pen you areleft with 12+ seconds of sitting doing nothing. On the JgPz E-100 it's ~21s before you can fire again.
I've got T10 TDs in the US (E3), German (JgPz E-100) and RU (Obj. 268) with only 70k XP left to get the FV215b (183) from the Tortoise in the British line. The JT is definitely the most consistent one for me.