Are investment property really worth the trouble?

It is not necessarily easy to find properties which cash flow well, but to make it worth it, that is what you will have to do. I am an appraiser and have bought and sold properties and owned rental properties in the past but do not have any now. I think you are smart to think this out instead of just jumping in. And , yes, in my experience, you will have to hold on to it a while. Don't forget to consider vacancy rates in your area- the duplex is not likely to stay 100% full for 10 years, you know. And the nuisance of dealing with tenants or hiring a management company (a nuisance in itself). It can work but in some markets, there are few properties which cahs flow well. Multi unit properties often cash flow better than single family homes but single family homes will resell quicker in most markets. I have been looking for over year for a reasonanble four-plex that will cash flow well and have yet to find the right one. Be patient.