It's great you are thinking about adding real estate investments to your financial portfolio. This is what I preach to anyone that has the ability to diversify in this manner. Though I am a local agent (San Jose), I represent a company, Nationwide Real Estate Investments (NWREI), which specializes in helping local and of the bay area clients purchase out-of-state investments.
The owners of NWREI have traveled the country extensively in order to qualify regions which they can with full confidence recommend. Besides having helped some of our clients purchase in North Carolina, we also have 7 other States and specific regions we recommend.
A key question or concern I would have is if you currently own Multi-units in the area. If a multi-unit is going to be your first investment to get your feet wet in these endeavors, I would respectfully tell you to re-think it.
If you like I can give you the names of 3 investors which you can contact which own at least one multi-unit or more. To get to the point, if they had to do it all over they would not go this route. They have since then focused on newly constructed single family residences (SFR's) and are diversified in 2-4 States or in the case of an attorney he is wanting to sell his Multi-units and create a portfolio of SFR's (these will be his new multi's).
If you are curious as to why or how this could happen please see my blog on active rain site: http://activerain.com/blogsview/239028/Multi-Family-Unit-Inv
(this blog has a SFR portfolio scenario).
Another aspect to consider is to diversify. It is not a good idea to have all your investments in one State...look what has occurred in Arizona, Las Vegas, Colorado, Florida...etc. Or if the purchases are within the same State the regions should be geographically distant from one another (many different micro-markets can exist within the same State).
Going back to your original question about the Triangle area...both the Carolinas are excellent for long term investing. Many businesses continue to relocate there and unemployment is low, while salaries are well above the National Average in certain areas. There are regions in NC that are becoming saturated by investors. For example some areas in Raleigh and Durham. Certain areas in Charlotte as well. If you are truly interested in pursuing this route even after careful consideration...I highly advise you to take a trip there. Meet-up with a very reputable broker and drive around for 2-3 days. Drive not only within the main city (i.e. Raleigh, Durham, Charlotte), but visit the suburbs of the main city. This will definitely give you the best indicator of where to purchase.
Talk to a couple of property managers. Find out the true rents and environment in each area you are considering (crime, economy, median household income, schools and job growth. Discover the tenant turn-over rate for multi-units in that region.
I wish you well on your real estate endeavors. Please feel free to contact me in order to obtain names of multi-unit owners or to discuss your RE interests further.