I myself have had only a few problems so far.
Good points:
Range is better than hub 4,
AX offers higher bandwidth than ac.
2.5g Port is very handy.
Passively cooled.
It boots faster and the UI is faster.
Down sides:
If I so much as change ANY setting in WIFI (other than the name):
I will loose 5G completely or...
I'll have 5G but it wont let me connect. Only a pinhole reset will fix this.