When you all are buying lists or collecting parameters for your data, what filters do you find to be the most efficient?

Trying to figure out the most efficient way to do all this and ensure a seamless (ie minimal pay interruption) transition. 

After working wtih many CRMs and REI's throughout the country, what I have learned is that the most successful companies have a unique, efficient, and disciplined process.

As @Tom Shallcross mentioned some of the factors that go into the rate, another factor is how many units.

His book really isn’t about long distance investing as much as creating systems to invest with more time efficiency.

Another factor is egress for escape in fire.

Maybe consider a SFH outside an HOA with enough lot space to add an efficiency or mother-in-law, or convert a garage port?

Smaller units like that generally run less efficiently and have higher risk (1 vacant unit is 12.5% vacancy rate) and should therefore have a higher cap rate.  

Time is the key factor.

Another limiting factor is whether or not a condo is FHA approved.I've helped several of my clients buy single family homes and rent out the extra 2 bedrooms for $400-500 a month plus utilities.