In the quality B class neighborhoods I was invested in during the last downturn, rents stayed the same in 2009, but went up all other times, and I missed exactly zero rent payments; in the C-class properties, rents didn't go down, they stopped ...

I don't think you could do it with a fourplex either, unless you buy it in bad shape and make significant improvements. 

However, my area is nearby to that of @Christine Swaidan's, so the trend may be different in your area.The general idea is that because CA is so tenant-friendly, and because our property costs are so high, one bad tenant can wipe out months - or even years - of profitability.

@Ken Otsuka how bad is it?

I'm not living there, so my concern mostly is it being rentable, quality of tenants, and resale.

We have significantly cheaper real estate in a lot of areas here so don't get caught in a bad buy just because of the prices.If you like I have an email that I can send to you that breaks down pretty much the entire city by zip code of the different type of investments you can find (will send to anyone).I also do a market report every month that I present at several different events that I could send you as well (will send to anyone). 

It is only deemed bad for lack of being good.

They charged a much higher price than I did (although I received much less profit) which wouldn't have been so bad but they couldn't seem to get it rented very much, plus, even when they did, there were always last minute cancellations (maybe found a better place for less money?).  

Tank less water heaters are more expensive to install and way more expensive to repair.A rental with tenant paying utilities should only have the most basic equipment supplied.

Seller wouldn't be coming back soon.Nick felt bad, but the realtor knew the scenario - guy had to sell.