Have t looked into the POF in a while. The new gen 4 has some cool features. Anybody try these yet? Curious to know if they are more reliable than the first ones,

This is the first time I've seen POF's reliability questioned. I'm very interested in seeing what I must have missed. I've a Gen 2 POF P-415 with over 1k that's been 100% reliable and sub MOA accurate. During my research of piston ARs had I found anything regarding reliability issues that testimony wouldn't exist.
ETA: Disregard... I overlooked the "308" in your title.

I have gen 3 pof 308.  Rock solid reliability wise. Also surprisingly light. Accuracy, I am not sure yet.  I am working on custom load and had no luck so far with weather.  Always very windy.   50 yards it's 1/4 to 1/2 Moa.   100yards 2 inch.  

Also, IMHO. Pof quality is bit own comparing to few years ago.  I would say my gen 1 pof 415 is awesome. Sub Moa and 100% reliable.  Fit and finish is perfect as well.

My new 308 is not perfect. Bit of free play between upper and lower and finish is not perfect.  

Having said that, I paid $2050 for it, so for that price, I am happy.