While quality work is not mutually exclusive to adding more features to a property, I have seen a lit of flippers houses that seem to do just that: add a hot tub, but can't seem to mount a toilet securely to the floor, or leave the 20 yr old furnace.

Nothing wrong with being tired of toilets trash and tenants as they say.  

A midrange kitchen remodel has a 96% ROI, costing an average of $27,492 and adding $26,406 above your cost in value.You could also go for slightly larger rehabs, such as adding a bathroom or a bedroom.

Rehab/remodel and selling is usually a decent exit strategy in Colorado, where good/quality inventory is always low. 

Since it’s also on a corner lot, it will connect the SoMa neighborhood (all their restaurants and business) to the Pettaway neighborhood where $15MM in new commercial/residential spaces are being built on top of a VA hospital remodel to 140-160 luxury apartments (70+MM rehab) that is just 2 blocks away.Willing to share more information at anytime. 

From the paint, to the floors, to the kitchen/bath remodel I'm sure it all looked great. 

Complete remodel, added half bath, added new systems.

However, the attic does not have pipes to put toilets, sinks, etc.

I have to find out with inspector(s) anything else but I was told there is no deferred maintenance and 6 of the 8 units have been remodeled.

I'd lean towards a full demolish as well...either way, headaches, but I'd rather have ground up headaches than remodel headaches ;) not to mention speed