It is like bet on red and win, bet on black and win big.The caveat is that while San Diego has historical appreciation going back more than 60 years, the appreciation goes in cycles. 

If you are renting C or D class properties, tenants likely have credit challenges.

Buying C-class properties (or even D-class) in up-and-coming neighborhoods is an excellent strategy, but it requires a strong understanding of where the market is, where it is headed, then buying in the path of progress, and riding out the storms until the progress arrives. as it relates to SFR props its quite rare that C or D class ever get better..

There are some large beautiful historic homes in LR that you’ll see on the MLS but they are going to be in C- or D zones, unfortunately.

I personally think solid B housing/B neighborhoods/ B tenants are the easiest work of all, and it has good returns - but not as good as C or A, which I think is more work for different reasons, and definitely not as good as D.

Also check with Hoa to make sure rentals are allowed, I would bet only 30+ days if any are allowed.

The trick is buying with the intent of going Section 8 (picking the right bedroom counts, NOT going into C or D neighborhoods, and rehabbing for higher abuse) and screening the tenants just as thoroughly as normal.

Don't bet on appreciation.  

The referral from your lender is probably your best bet on this one, but I'd want to see some of his work.

***Only exception is if an owner has plan & funds to reposition Class D to Class C or higher.https://www.biggerpockets.com/forums/776/topics/960183-what-they-dont-tell-you-about-cheap-rental-properties?