Go go go. You will not be disappointed. Arsenal is by far my favorite place in Pittsburgh. Great drinks, awesome atmosphere, and a successful small business.
My number one spot to take any visitors. Every single person that comes to visit me in Pittsburgh has been to Arsenal. No joke. And everyone loves it. My cousins wife still talks about the place 6 months after coming here, and can't wait to come back again.
Not a huge fan of cider? Don't ever let that deter you. The Hop Cider I.P.C. tastes just as good as any IPA you can have at a regular bar. And from dry to sweet, your cider needs will be met. I haven't yet experienced a night in the backyard (great food and local bands, how shameful of me?), but I've heard so many good things.
This place just continues to get better and better as time passes. Get a growler (or three if you're me, I need to start carrying them in my car for those spontaneous trips...), and drink your cider, no better place to spend a summer night in the city of Pittsburgh.