xoshiro has flaws: http://www.pcg-random.org/posts/a-quick-look-at-xoshiro256.h...
The other parts of the post definitely concern me about using the PCG's described, though. Also, it's interesting to see how PCG can be predicted. I would not have known how to attack it.
Edit: And I like that MCG with 64-bit multiplicand that she shows. I might switch to that for Monte Carlo applications.