Yes user-wise they do seem to be doing fine, but I'd like to know where the growth is happening. That's important.
The 2nd source has some interesting demographics, but unfortunately doesn't include growth which would be the most interesting to me.
Very interesting that their largest user base by far is now in India, which I hinted at before. I suspect much of their growth from their latest earnings report is from that region of the world. Which also helps explain why ad revenue is down. Note also that ad reach in India is a very low 30% compared to the UK at 60% or Mexico over 80%. They didn't give numbers for the US. But if a lot of the growth is in India with such a low ad reach, that doesn't bode well for ad revenue.
Facebook also seems to be failing at attracting the young demographic from the west that advertisers love. As their core user base ages it will be interesting to see if they can maintain the interest of advertisers. I think Instagram is going to prop them up for a while. But it wouldn't surprise me at all if Facebook starts to become less important to advertisers, who will quickly move to wherever their target audience spends the most time.
Either way, just because FB is doing fine user wise doesn't mean that folks on HN who threatened to quit FB didn't actually go ahead and do that. If every HN user quit FB in one day, I don't think it would even show up on any chart.