Within 5-10 years you should have been able to pull out your entire investment tax free and earn an infinite return. 

How do your actual returns compare?  

The returns will likely be greater if you source the borrower and originate on behalf of the IRA.

Not a bad return from appreciation alone. 

While @Phillip Austin mentioned Raleigh is a higher returns its just very much a appreciation market, you will not find rentals that cashflow, so depending on your goals its a good or bad market.

That said, what is not clear is whether your CPA prepares a partnership tax return for the deals where you guys partner up.

In this order I would analyze the rate of return. 

Quote from @Fred Scott: Sunrise Capital Investors - Mobile Home Park Investment FundI've seen a few posts about them here but none of them actually talks about what the actual annual returns have been.They are advertising heavily for passive tax deductions which is fine but what are the actual returns over a period of (say) five or ten years?

Starting local offers hands-on experience and control, ideal for learning the ropes, while out-of-state investments can provide better returns but require a reliable property manager.

Thus, your return would be about 11%.