I'm personally not a huge fan of Four Peaks. I've never really liked the food all that much and I find it to be more of a hassle than it's often worth to go there and find parking and get a table. It's not always too busy, but most of the time it is. That's the price you pay when you're popular.
The beer is good enough to be proud of if you're a local and you don't have to get it here since it's sold all over the valley. I wouldn't ever go out of my way to get it, but "good enough" is about the best compliment I can bestow. I'm not a huge fan of beer to begin with, but I like it enough to have an idea of what constitutes a good beer versus a bad or average one. Some of their beers I simply don't like - it's that stomach bile flavor that turns me away. Other brews are quite tolerable to actually good.
I see this mostly as a great place to take someone who is visiting from somewhere else. There's a bit of a 'wow' factor with Four Peaks. It's sorta neat to walk in through the back door past all the tanks and whatnot. In the summer, it's also a nice and chilly way to cool off. Beyond that, it's probably only barely worth it. I've found the service to be unpredictable... usually not good. It's probably a bad idea to take a date here unless you're in college.
When my friends suggest going here, I usually suggest someplace else - not sure exactly why. There's just something about it that doesn't lend itself to an easy dining and drinking experience... it's complicated somehow. It's odd that a place you can wear flip flops to could feel complicated, but it is. Maybe it's that tiny bit of 'factory' vibe the building gives off. It's like we're visiting the building while it's working and we're not entirely welcome there, but it's just too polite to tell us to leave.