So, my primary factor is job history & criminal history.

The same can be said buying in B-class vs C-class properties, there are pros and cons to both.Part of it will come down to the area you invest in, but the biggest factor is your personal one - what do you like best? 

The vacancy factor is important to note on the effect it has for a particular month, but from a long-term analytical standpoint, VACANCY shouldn't necessarily affect your decision of 1 vs multiple properties (given the properties are in the same location and the vacancy rate is the same for each). 

Unless the siding is dented to pieces, no way is it going to help your appraisal by anywhere near that factor. I

Do you know what the risk factor is on those notes (in general)?

(Also when the trash pick up comes).If the area has a good market for rooms, you vacancy factor is more like 0%.

However, I think the most important factor is finding a good Loan Officer. 

Ok so with the above, you lose about 1/2 the buyers, the counter top that is lame causes many buyers to be like 'Tear down, this whole place is tear down!"

There are a few advantages each has, but the primary factor is to look at the ones in your area and determine which will give you a better rent to price ratio.

Ignoring this factor is one of the biggest mistakes I see outside investors making when buying in the STL market.