I still have a lot to learn, only level 30, but wanted to share a few things I've observed.
One is that any mob that drops weapons or armor has a chance for those weapons/armor to be upgraded. I think most of the legendary drops are level 20 or 25 to start, but the epic ones can be lower and have good mod 2 and damage and stuff. The legendaries have a ton of stats and seem to be randomly generated? Or otherwise there is just a hugely seeded set of items. There seems to be no standardization at all. I think legendary always have heroics, mod2, a abilities/procs/focus, but the amounts and types of focus are all over the board. Ratios also seem to vary wildly. Just on one handed at low level, most seem to be in the .3-.5 ratio range, but I also found a 2.0 ratio bronze sword once.
Potentially fun as legendary are pretty rare and seem like a total lottery ticket. I found a sword that procs thunderclap (aoe+stun) and it's just pounding. Proc rates here are also super juiced compared to live. And the proc levels are adjusted. Thunderclap is a level 30 spell and it's working at 25 on my sword.
Spells also seems adjusted. The 18 bard aoe song hits for 106 or so at base with a horn. And now at 30 is hitting for 150 or so. Probably a lot to discover there.
My paladin has a combat ability for 1h that is totally custom. It gives a 1hr buff that is just wild. It procs a heal, gives massive increase in melee damage, in block, and makes your spell damage a lot higher (I think 3x higher)? Yet to see how well elements of that scale, but worth noting that some classes may have cool custom abilities. Similarly my rogue has a custom heal buff and a poison proc buff.
Armor is also same. So it's a good idea to hunt in areas that can drop whatever you're after. I have like a full set of bronze legendary from unrest.
They changed discs to be available at lower level. Most seem to start coming online around level 15-20.
Regen seems super juiced as well. The regen ticks (perhaps related to bard song - couldn't tell) heal for 20-30% of my life or so as a newb.
Assuming twinking is totally crazy. But the normal playthrough towards 50 feels pretty good. As I mentioned, I think reds are harder than in live, and blues are easier. It feels like their atk/defense penalty/bonus relative to level is more extreme. Ive been 3 boxing ssf and could kill many blues (4-5) in crushbone two yellows might kill me. Also, deep reds have a bonus against you and are significantly harder.
The economy is not nearly as newbie friendly as THJ for whatever reason. Finding traders with newb gear is hard and I don't see stuff that is under a few hundred plat very often. And you have to pay a big premium or run to the bazaar (PoK based).
Overall I've been enjoying it. I think starting off untwinked and solo would be somewhat challenging. On THJ I thought you could accidently level too quickly and be in an AA deficit and find it harder to progress. Will be interested to see if that's an issue here.