Got it earlier, played about 3 hours, got to lvl 70 and started to use some items I had already kept for that (non-season of course).
Most of the items I use are for the Wizard but in the meantime it gets the job done since the Necro's primary stat is Intelligence. I haven't tried many builds obviously, and I didn't try it during the PTR so it's completely new to me (well, new in D3 that is, I played some Necro in D2). I mostly tried the 'typical' Necro Army stuff and so far at least for that sort of playstyle it works well. I can Revive up to 10 enemies I killed and they follow for some time (19 seconds default... and 12 seconds with a Rune that increases the Revived enemies' damage, but it's weird that they didn't just go with 20 seconds for default, why 19? That extra second made everything OP or what?), that's alongside 7 skeletons I can get as a Passive (and can be Activated via Runes for different Activated effects) and if you want there's another skill gives a Skeletal Mage for a couple of seconds (one specific Rune I like with that one consumes all of your Essence and increases the Mage's damage by 3% for every point of Essence consumed, reminds me of my Boulder Toss build for my Barb).
So when it comes to getting my personal army, it works. I haven't experimented much with that type of playstyle yet, only tried some Gems for Pet damage and Cubed Tasker and Teo gloves for Pet attack speed, if you combine that with a fast 1-handed weapon and a bunch of added Attack Speed bonuses from gear it gets hilarious to see your 7 skeletons and your revived army attack so fast I swear they swing 3 or 4 times per second (one of the Activated effect on one of the Runes for the skeletons focus them all on one specific target and their attack speed is further increased by 25%). I don't know what's the attack speed cap on the Necro pets, it's probably the same as any other pets from all other classes but I never bothered actually checking around for the stats about that. But it's fun, that's what matters.
When it comes to Corpses, it's pretty much all there. I haven't used a lot of the Runes for the Corpse skill but one I do like creates a passive aura around you that automatically consumes corpses around you and grants more Essence, which is good for spending it all in one go with the Skeletal Mage skill. But other than that I still have to play with that more. There's the Bone Armor and Poison stuff too. From what I've seen most (although, not all) of the Necro runes are Poison and Physical, some I believe are Cold. There's no Lightning though... and I'm not sure if there's any Fire in there... I'll have to check again. But the gist is it's mostly Poison and Physical, which is probably similar to the Witch Doctor.
I just started though, and the gear I'm using isn't providing anything specific for the Necro yet so everything I use and do is very basic. When I start getting the Set items and the Necro-specific Legendaries I'll start experimenting more. For now I'm 'stuck' to about Torment 8 or 9.
Overall though, so far, it's pretty solid. I'd give it a good 7/10.