State requires you accept paper checks)Simple to use Maintenance requests so they stop sending post-it notes with the rent.The ability shut off payments, or even better block partial payments, in the case of rent arrearsNice to haves are:The ability to securely share documentsBlocking Partial PaymentsNon-ACH online payments, ideally without having any additional setup on my side.I already do all my accounting in a properly double-booked accounting system, so that isn't a priority. 

I've walked neighborhoods where block after block, every single MF had one...on both sides of the street. 

You can also buy a plastic block to assist with hamming the boards.

I am adding some sqft on the second floor, although the addition I am doing on the second floor is very small and shouldn't really block any neighbor's view, there is still a possibility where someone may raise objection.

In Scottsdale there is a valid concern with STR's, as some tenants are throwing loud, late night parties- some of which have cars blocking the roads and neighbors' driveways, etc.

@Anthony Mei There is an exemption to reduce the 2,500 s.f. per unit to 1,500 s.f if 60% of the block has 2 flats.

A couple blocks around where you grew up is the first place that comes to mind.

On older units it is often low Freon levels or can also be blocked air return or clogged air filters.

the lady had a 9 acre piece of ground blocked. 

Which blocked the smell, until I returned to the property a week later and opened the door to a new smell, which was a combination of cleaners, primer, paint and cat urine.