Philly rezident here. This city is awesome for beer pretty much always. I've been to a few beer festivals. Generally it's great fun and awesome for networking/meeting friends/getting free swag, but it's definitely not your only opportunity to enjoy a variety of good brews.
Downside is that it's kinda expensive, and definitely a sensory overload as far as tasting beer. Those tiny cups and long lines will drive you crazy the first hour, but then it's all gravy. You will get to try everything.
Best thing you can do is bring a notepad and take notes on whatever breweries, styles, hop flavors, etc. so you can follow up on it later.
In the future, keep an eye out for upcoming festivals and contact them about volunteering. I've done it a few times and it's a great way to save $50 and feel important. Cheerz!