Job offer? I'd look to keep the commute short. Traffic on 405 during "rush" hour is glacial. Whidbey is isolated due to topography. There is one bridge at the north end. All other access is by ferry.
That said, Whidbey Island is gorgeous. The isolation is part of its appeal. It's dotted with small towns that cater to tourism. One of our favorite stops is Fort Casey, constructed in the late 1890's to protect the sound from attack, now a state park. There is a Naval Air Station in Oak Harbor on Whidbey as well.
Just depends on where you are working. North end traffic is horrible, actually any traffic around Puget Sound is. Whidbey is beautiful though, great parks, trails, beaches, biking, etc.