We've flown on the Horizon operated Q400 several times LAX-STS and SAN-STS. Very nice service although as mentioned above there's not much in the way of complimentary snacks. The complimentary microbrewed beer was also fine.

Santa Rosa has a wonderful little airport which is quite user friendly as well. I also highly recommend the airport café if you have enough time. Last time we flew out of STS, we had breakfast there and the food & service was great.