There are many duplexes and multi-family existing housing available to choose from. 

There is some truth to that, but that rhetoric largely came out of a massively long bull market with historically low rates.

Pros: Diverse job market, low unemployment, great resilience during recessions, nice appreciation, 1% rule can be hit if you look hard enough, great economy, good schools, Midwest nice.Cons: Extreme weather at times (hot/humid summers, tornadoes/hail, brutal cold in Jan/Feb), high insurance premiums, property taxes also really high.

Low property prices evidence this.

Save them all..if you ever decide to do a campaign of your own, you will have good examples to choose from.

A good builder will have some solid plans to choose from that your property management company can review and maybe tweak.   

While the prices of home are low, rent yield is still strong making you feel more confident in achieving those cash flowing goals. 

I did this in the MS market and while the advantages you pointed out were true.. markets that have slow appreciation and or areas where builders can keep building for low dollar amounts like the mid west.

Even if these people know their property is worth more, there is sometimes that one owner that wants the windfall of cash they have coming and will take that low offer. 

Expect to spend a considerable amount of your time speaking to people.Expect to work dozens of hours/week with little to no immediate result.Expect most of your early interest from potential clients to come from your sphere of influence.Expect to go 3-6 months without getting paid (unless you do rentals which usually pay faster)Expect to be bombarded with distractions - mainly, people/companies marketing to you so that you choose their system for quick and easy buyer or seller leads.