Also I am concerned about them becoming just another part of the rust belt that does pretty well in good times but hits tougher times during a recession. 

Im not playing in SW WI, but i do in Northern WI, you really need to know your market and numbers, compas are tougher to understand, but I do well im my markets, the majority of my portfolio is either rural, or in towns below 15K people. if you have a good team and a PM that operates at a high level, those markets can be gold, but its not for everyone, its not easy, but generally there is little competition and high demand@Michael B. population of 70K is quite big in most of WI other than Milwaukee, Green Bay, Madison and Appleton, there are not many cities north of 50K populations. 

My sweet spot here is $100k - $170k because I don't want to mess with the under $100k crowd and I think it rents above $1,700 will be tougher to fill.

I run a real estate and mortgage brokerage out of LA specializing in working with investors and love the challenge of figuring out tougher cases.

If anyone else is interested, you can see them here: https://www.biggerpockets.com/blogs/4837/43935-everything-you-want-to-know-about-buy-and-hold-real-estate-presentationIt's tougher to find such deals in this market and you'll have to dig more (probably do some direct-to-seller marketing), but there are always great deals out there.

I'm sure in 20 years, these prices will look like steals, but today they are tougher to swallow.

A short sale makes things tougher, generally the owner has no money (which is why it is selling less than they owe) and I will just about guarantee the bank is going to say "no" if you even get a response.

In terms of a 100% cashing out, that question is tougher to answer. 

Net migration is due to increase in the next couple of years and tougher mortgage rules have forced potential first-time buyers to stay in the rental market.

The numbers always look appealing in tougher neighborhoods, and some folks make money there.