With class C, a lot.Below are charts showing median $/SqFt sales and rental rate trends for the properties that we monitor.

As a longtime, seasoned real estate and note investor (as well as mortgage company owner) we certainly monitor taxes (and insurance, too).

Also areas with high crime are very hard to manage/monitor/access...did you check the crime map for the areas?

ExteriorThe walkways were cracked and should be monitored for action.Sections of the aluminum siding and trim were damaged and should be replaced.There was weathered wood trim throughout that should be replaced as necessary.We recommend installing window well covers over all window wells.The left-side gate was damaged and should be repaired or replaced.Some of the hose spigots were inoperable and this should be corrected.There was some minor cracking throughout each driveway that should be repaired as necessary.There was storage in the 1070 garage that obscured some areas from visual inspection.The Genie overhead garage door opener was not working properly and should be serviced or replaced.The garage door opener was plugged into an extension cord and a dedicated outlet should be installed.We recommend installing downspout extensions to divert drainage away from the foundation of the home.Each overhead garage door was damaged and should be monitored and repaired or replaced as necessary.The patio screen door was badly torn and damaged by the dog and should be replaced.The left side storm door was missing and should be replaced as necessary.

Managing my flip crews, monitoring my rentals and looking for new opportunities.I am very interested in Multi Families 20 + units . 

I would say about 5 min per month to 1 hrs, and that is strictly to monitor the property manager.

This year, my immediate goal is to purchase an additional multifamily dwelling (possibly before July) as daily, I monitor the Fed.

This may be a good option, if you aren't trying to share the access of an existing realtor (most systems monitor/restrict concurrent logins).

Analyze every single house in that market, then do that again.This will help you identify typical houses, prices, rent ratios, tax rates for different parts of town.It will also help you to understand if a market you thought would be of interest is in fact relevant for you.Now that you know what is typical in your market, keep on monitoring and start noticing the things that are a-typical, That's where all the interesting stuff happens.

@Seth Leiboh I target an area, monitor the traffic and let everyone know what I'm looking for.What's your "initial review"?