Please note...
A little note on tire pressure gages. They aren't all created equal. Just the opposite and just because it's a digital one, that don't mean it's good to go either.
I use a Wikka glycerin filled gage (which is a true Burdon tube gage). The glycerin is just for dampening pulsations and isn't really necessary. I have the gage coupled to a foot long whip hose with a Milton air chuck on the end. Wikka gages are industry standard for accurate pressure measurement and are ISO certified. They aren't cheap either. I believe the most inaccurate gages are the slide type pencil gages. The friction of the moving slide can acerbate the inaccuracy. I've compared the Wikka to a Milton slide gage in the shop and have found a 5-7 pound differential. The cheaper digital one from Auto Zone is better at 3 pounds, but I prefer the analog Wikka gage.
I don't see any advantage in filling your tires with an inert gas other than if you want to spend extra money or if you are running 200 plus mph., day in and day out. Save the extra bucks and buy some beer.