Signs that they are trying to hide a foundation issue suck as patched over cracks and paint that doesn't quite match in these areas.

Of course it's cheaper to just paint over the panel walls and remove the popcorn ceiling (which is what I was planning to do), but now I'm wondering whether it's worth the $60,000 investment to remove all panel walls and replace with fresh drywall and fresh paint in every unit. 

We completed a cosmetic rehab including replacing the kitchen, bathrooms, flooring, paint and adding recessed lighting.We funded this project using a conventional loan and using our capital for a down payment and construction costs.

As I get my feet we out of state I would like to do more simple rehabs (minor repairs, flooring, paint, maybe roofing, etc) and am okay with more in depth rehabs later. 

Updated upper unit with new kitchen, bathroom updates, fresh paint, new windows and new lighting What was the outcome?

Agreeable Grey for a long time was the color to paint rentals, that is changing.

I'm glad I didn't take the cheap route (a repair person to sand and re-paint cabinets or reface the cabinets and install new countertops).

The tenant fails to pay their last month's rent and leaves the place needing new flooring and paint.

I would either look for something turnkey or one that needs minimal work like paint and flooring, updating light fixtures and small things like that.

Backup tiles, paint, etc. provided so owner will have the exact match in case of future repairs or touchup.