Finally finished it last night. I felt like the show took it's sweet time getting anywhere but it did get there around episode 11. I assume the show didn't want to make Frank look like one of those gun nuts who go on a rampage but Frank was less murdery than I was expecting (to the point that it was weird). It seemed like there were was a long stretch where he didn't kill anybody.
But by episode 11 they gave us the Punisher we want to see IMO. Despite my complaints there needs to be a second season IMO. There's 2 parts to the Punisher...avenging the death of his family which is personal and then him moving on to his true purpose in life which is his mission against crime in general. He hasn't gotten to that level yet IMO and he's a little half baked until he gets there.
They did a nice job showing that Frank is still human despite everything but that deep inside lurks the killing machine that is the Punisher.
Now if you want to see Frank in more of a rampage mode, rewatch Daredevil Season 2.