However, if the LLC depreciates the property each year, the member's accounts will reflect much smaller amounts, potentially zero growth each year. 

Especially if you are talking multifamily units.In the next twelve months, we have the goal of 10 flips/wholesales netting an average $20k profit.That should double every twelve months and once at the point of seven-figure liquidity, we have our eyes on commercial and massive multifamily units.With the growth rate of North Texas and the lovely business friendly state governance we have, it should continue for the foreseeable future.

Yes thanks to the  Economic Growth and Tax Relief Reconciliation Act of 2001 (EGTRRA), former employer plans can be transferred to IRAs. https://www.irs.gov/retirement-plans/determinations-summary-of-egtrra-changes-for-retirement-plans

The two things that come to mind is the current cost for properties in the area and the growth potential of those property values.

For us, it is Job Growth, Population Growth, Landlord Friendly laws, Capital Investment by the City, Capital Investment by Developers... all of these things come into play when looking for a good investable market for us.  

I figure once I get 2-3, I can take a HELOC or something of the same substance to continue my portfolio growth.

That indicates that rent growth is probably going to disappear. 

DC however did not start it's path of growth until the mid 20th century, and had plenty of available land, so it was able to grow with suburban sprawl as opposed to other cities with less land to spread out onto.

There are a lot of people that see value here.Some people may not be impressed when they consider investing here, but if they take a deeper look at the local economy and growth that we have, it makes our market look great.

The market upturn was responsible for most of that growth, and we are now in a 330 house that has an attached apartment.