Diablo 3

Absolutely. I can't fathom going back to sc. I was at the top back before paragon levels, when dying meant a lot more, but now with paragon bonuses, I feel there's even less excuse not to play hc. You're always progressing and never truly "lose it all". Your efforts are never totally in vein. To top it off, I used to play vampire bat doctor, so I was always tanking up close with the most anti-disconnect build possible, on an unstable 3mb god awful internet.

After a year long break, I came back to the game, logged in to my 300 hours played WD and started taking a look at the newly implemented grifts. 30 minutes in to my return, my internet lagged out and I died. Absolutely the worst way to go, but it legitimately didn't bother me for more than 5 minutes because those 300 hours kept me so much on the edge of my seat and more entertained that I just couldn't compare it to my sc days.

In terms of positioning, it depends on what the current meta is right now. The last time I played it was all about my favourite build so far, the mass fetish dagger doctor. If you're doing that, I can tell you about literally everything the build is about, although in pbe back then, people seemed to be leaning towards some new op poison zombie build because of a set bonus change.

One thing I will say about playing hc, is playing with a group is obviously infinitely better than solo as a disconnect counter measure. Probably about 60% of the time, I was in a group with friends on skype/discord and the second we noticed someone drop, we always rushed towards their character to defend the area until their character disconnects. Of course you don't have that benefit in solo which makes it a lot riskier.

Cudos on trying to do research by finding a streamer, that's absolutely something I recommend to people and do a lot myself when getting in to new games (like blade and soul right now), but D3 isn't exactly a fun game to watch, so its streaming community isn't particularly en masse anymore, maybe occasionally HC because people like to watch others die, but yeah. It's not really the same and I don't find it as entertaining, but I imagine there are a lot of youtube vods where you could achieve the same educational end result.