i'm sorry but I could not resist...!

Heat pumps can yield an effective efficiency over the heating season of more than 100% (in comparison to traditional resistance heating) ... in a nice, mild climate like Maryland, a good heat pump should be able to produce an average effective efficiency of 200+%.

I would love to try to get the cheaper one at a lower price and do a full renovation which would allow me to custom the unit as I want but I'm resistant because I've heard horror stories from people who did renovation loans where it took a ridiculously long time or the quality of the final work was poor. 

While landlords hate to drop rents, and resist it like the plague, make no mistake that during a downturn your income will fall even if you don't drop rents.Vacancies will increase, credit loss from non-paying tenants will increase, eviction costs will increase, you'll have to offer concessions like free rent or temporary discounts to attract tenants and keep the property full. 

I would not put in sheet vinyl, but would use vinyl planks that look like wood and is water resistant. 

I'm concerned I'm going to run into resistance (some units are $300-$400 under market) and potentially tenants who decide to just stop paying and use the COVID moratorium as an excuse.There are 12 units total.

I liked it because I could improve my lifestyle, while still resisting lifestyle creep and buying two units with one deal.Investing in Duplexes, Triplexes, and Quads by Larry Loftis.

However, electric resistance heating is a big negative, so I agree that replacing that system is mandatory.

(Though admittedly sometimes landlord resistance causes other decisions to be made.

They are way more efficient than resistance heating and are also A/C in the Summer, which can be a huge selling point, depending on where you're located.