Cotati is very safe and quaint with a laid-back vibe. We've lived on Santero Way a few years. With Sonoma State just down the street, however, you must keep in mind that it's predominantly a college town. College kids rent all over and are loud. Other than that, it would still be a nice place to raise a family or retire. Oliver's Market is a main attraction in this teeny town and the only thing open past 9pm (besides the bars downtown). You have to drive to downtown Petaluma for dining and a bit of culture. It will be interesting to see the changes once the SMART train is built- since there's a stop planned for Cotati....

I lived there temporarily while doing a teaching credential at SSU and I loved it. Its smaller than the surrounding towns but keeps its own culture; Cotati's safe, cute, friendly and has lots of parks and is very accessible. Its not as fancy as Sebastopol or parts of Petaluma or Healdsburg, but it keeps its property values more than RP, and is only 30 minutes from the ocean. Its student friendly, which may or may not be what you are looking for. When I lived there my neighbors bothered to introduce themselves, that was nice.

Hi there Elizabeth--you are doing good homework researching so many communities in Sonoma County. I commented on some of your questions the other day, including some you may have missed from the first post that went to Arizona. ;)
Cotati has many types of housing stock from small condos to more conventional homes and homes on acreage on both the east and west sides of 101. You can check out my country property listing on Gillmore under my profile. It is west of 101 in a very rural area on the main road to Sebastopol. Most of the housing is East of 101 between Rohnert Park and Penngrove. Both Cotati and Rohnert Park are influenced by the presence of Sonoma State University for faculty and student housing, as are other nearby communities to a lesser extent. Also, from here people can commute to Marin County or the Bay Area more easily. Ages of homes are similar to the other communities you mentioned with fewer vintage style homes (except on acreage). The Trulia stats and also the Altos Research stats on the home page of my blog (below) will show median prices by quartile in most of these communities and I can pull other stats for you if you like. If you are planning a scouting trip to Sonoma County, please let me know and I would be happy to help you get oriented further, as it suits your timeframe. We have so many small communities within a short distance of each other that it would be helpful to understand more of your tastes and concerns so as to address your questions most effectively. Hope this and our other answers have been somewhat helpful!