Biggest differences in buying a 6 family over 2-4 family?

[Steve Candor]

Saw a pretty good deal on a 6 family property that is pretty much turn key and generating great cash flow. 

What are the significant differences in investing in a 6 family over a 2-4 family property? 

[Jerry W.]

The way they are valued is not based on selling price  per square foot of other rentals, price is based on the amount of income they produce.  Cap rates.