I personally liked UTC a little better, but Irvine is quite nice. There are a lot of similarities between the two such as a UC Campus, huge white-collar job center, lots of upscale apartments/condos, and an overall clean, sterile, prosperous feel.
As the others said Irvine is fairly homogenous and I wouldn’t say any area is bad. The school district is highly regarded. The crime rate is one of the lowest in the US for cities over 100K in population. The people I have met are mostly quite nice (but also more homogenus than SD). Traffic is really not an issue if you both live and work in Irvine. The surface streets are nearly always fine. If you have to get on the freeway rush hour can be fairly bad. There are nice neighboorhoods all over Irvine and if I were you I would choose something close to work.
Prices are definitely higher here than all but the nicest areas of San Diego. During my own search I found prices to be 10-15% higher than UTC on an average for comparable units. I rent in an Irvine Co apartment, and am fairly happy with them. They seem to charge a little more, but have good service, low security deposits and flexible leases. 6 months ago when I was looking there were not many good private party units on craiglist, but there seem to be more now so I would recommend you take a look.
