I'm a NYCer but was in San Diego this weekend and ate at Region & Chive.
Region: worst service ever. It took over 10 minutes for the hostess to just check us in. It was 9pm on a saturday night and tables were full but the waiting area was relatively empty. In the time we waited (I had an 8:45 reservation and wasn't seated til close to 9:30) we saw at least 2 groups leave because they got sick of waiting for the hostess. It also took the bartender over 15 minutes to take our order. Again the bar wasn't crowded. The food was solid. Due to the late hour a couple of things we wanted to try were sold out but the salmon and salad appetizers were very good. the duck confit was perfect as well but I thought the veal cheeks my friend had were a bit tasteless and mushy. The clementine sorbet was very refreshing and intensely flavored and a very nice way to end the meal (though i really wanted to try the apple crostada).
Chive on the other hand had very attentive service and a much more inventive menu. The bbq ahi app and the bloody mary gazpacho were original and flavorful. The crab shells were very rich and decadent and the sunfish was perfectly prepared,light with a great wasabi sauce. I'd recommend Chive any day but I'd skip Region and head to Parallel 33 instead.