Yup, it's tough without a crystal ball. I tell my investors to look for the biggest square footage, the largest number of bedrooms and the newest home. If you can buy that home in Natomas for cash flow with 20% down, and plan to hold it for a while, it doesn't matter too much if the market turns around. Cash flow is cash flow, and homes that require little maintenance are even better.
Natomas is closer to downtown than Elk Grove which, in my mind, makes it a better investment. But as to when the market will turn around and you'll spot the sparkling appreciation rate many hope for, I wouldn't count on any of it. That's not investing in my book, that's speculation.