Not much in the way of breweries up in Irvine area (used to live in South OC too). I've never been to the Bruery, but it seems to be well-liked. Skip the Yard house- mediocre food and a totally corporate chain. A great selection of craft beer of course, but the selection doesn't change much and there's nothing too exotic. Usually only a single example from most breweries, and with 100 taps, there's just no way any of the more obscure brews are going to be fresh.
I'd see if you could add more time in SD (but of course, I'm biased and not afraid to admit it). I'm WALKING DISTANCE to SIX breweries at my house (Karl Strauss, Green Flash, Ballast Point, Airdale, Hess, and Alesmith, but who's counting?) not to mention White Labs itself, which gives a pretty cool tour.
Just a few to pick and choose from while you're down there (!=personal faves, *=North County, so closer to Irvine):
Pizza Port!*
Stone!*
Alesmith!
Oceanside Aleworks*
Mother Earth*
The Lost Abbey/Port Brewing*
Green Flash!
Ballast Point!
Coronado
Airdale
Aztec
Coronado
Iron Fist
Hess
Lightning!
Manzanita
Mission
Alpine Brewing
As well as a ton of great brewpubs like your Oggis, BJs, Rock Bottoms, and Karl Strausses. Also remember that even from north county, it's never much more than half an hour drive to south county if that's keeping you from exploring farther south.
If you're looking for the absolute best in beer bars/pubs, with amazing food, look no further than the Blind Lady Alehouse in North Park. Stone, is of course, a must-go for a beer lovers and foodies (currently it's my favorite restaurant in the county, even though it's only my #2 or #3 brewery in the county).
Failing that, if you want a super casual non-pretentious experience more like a standard sports bar, you can never go wrong at the Tap Room in PB. Awesome selection of locals, great assortment of other craft beers, and some tasty pub food. Beer is always fresh there.
When will you be down?