I have been running him since he came out as my only Master, just to try to get used to him.
Zipp himself makes a pretty good assassin (attacks against opponents HT)
These same attacks can move models up to 5", so can get pesky models off objectives or out of the way
He can also give some models a movement boost (CA push for 8")
Excellent DF/WP trigger to try and keep him safe
i have tried both of his limited upgrades, really only choosing one over the other depending on what faction I am facing.
Like all crews, the models he sells with work pretty well with him, but i do not see any of them as Auto-includes. You will want 1 or 2 Sky Pirate models just to reap the free upgrades they can get from Zipp, unless you feel you have to run something different.
First Mate is great at taking down opponent scheme markers. This can really help against all of the newest Masters. You could run schemes with him too, but Merris is a better option.
All of my gremlin lists tend to start with a Taxidermist and 3 stuffed piglets. Strategies are the only things that would keep them off the table.