But they are a lot more difficult to find than 2 or 3 years ago.

Its going to be a lot more difficult to find a triplex or quadplex than a duplex.  

However, as you note, a portfolio lender who will retain the loan on their books as opposed to reselling it will be able to extend past the 10 loan cap. 

Low cap rates?

Even if you exceed the $500K cap you would only own LTCG on the amount over that.

I really like Dallas/Forth Worth and Raleigh/Durham/Greensboro market in NC (also have friends there) but it looks like it is tough to buy with a decent cap rate/cash flow. 

You can also go a step further with a commercial umbrella policy if your net worth calls for it.I tend to be more worried that rates will spike, sending cap rates much higher and valuations much lower. 

When I was content with my unit count and portfolio and buying more became difficult anyway I started paying off my highest rate and highest risk loans organically with portfolio cashflow.In RE, you have to make hay while the sun is shining. 

Cap Imp vs Repair Expense IRSI'm in the middle of doing some 2017 tax crunching last minute so of course I am on Bigger Pockets forum instead of finishing up my taxes :-)Anyways here's a useful tip on Cap Improvement vs Repair ExpensesMy strategy has always been to increase regular maintenance, repairs (Repair Costs) and spread out costs over time instead of the hands off approach to defer maintenance into larger Capital Improvement expenses. 

Also - it's going to be very difficult to cash flow on a duplex at a price of 660k.