Weeeeeeeeeeeeee! What a gem! My girlfriend and I were scouting new coffee shops to study/work at and we ended up at Biddle's. Zero work got done on our first visit, however. We had no idea there was an upstairs area!
We nabbed a table on the patio, listened to the live tunes being played inside, and enjoyed the sunshine and friendly pooches. Lines tend to get long and out the door here but don't let that deter you. It doesn't take all that long and it's totally worth it.
You honestly forget you're in Pittsburgh.
I ventured upstairs for my second visit and thankfully got a good bit of work done. There were about 3 other studious folks at tables up there, it was the perfect setting for production, aside from a chatty couple :/