The identity of the buyer is not the issue.  6% fee is not unreasonable. 

The best possible comp is the identical floor plan right next door.

A near identical property with slightly better features (larger yard, driveway and a little prettier) sold a week ago for full price, $235k with multiple backup offers according to the agent.The property is 12 yrs old and feels like a worn rental.

More attractive because it will be appealing to *SOME* SFR buyers who might occupy it and be able to derive additional income from it where a standard 3 or 4-plex would not.Less attractive because it will turn off many investors because they will want to standard building with identical units since it's less maintenance (under one roof).I am trying to debate whether I should stay with SFR or real MF, or consider some of these in-betweens?

Very uniform identical units. 

Or do you use an identical discount factor for all years on the same property?

They have your name, address, routing number, and checking account number.On a side note, I purchase the identity theft protection from Zander insurance that covers my whole family for $140 per year.

I might not have to have it, but DOB is usually used by credit companies help establish identity.

Here in DC two identical houses could be right next to each other, but if one was built by an architect/builder named Wardman, it will command a $50k premium.

If the idea of diversification is a good one, nothing is more diversified than having 10 SFHs of different size, construction, and neighborhood, vs. one 10 MFH unit of identical units and materials.