@Alexandra Reeves, in my experience, tape measure or laser measure is about the only reliable measuring device.  

Will you need a generator backup if there isn't reliable power there? 

You'll need reliable local contacts, such as a cleaning crew and maintenance professionals, who can handle on-the-ground tasks.

Regular long term rent: $750Airbnb ( only opened 2 months ago) : earning about $2800 on a not peak season. looks like it may hit the 4000 mark in April/May peak season....It is no more than 5 hours of work per week if you do it efficiently and find a reliable cleaning crew.

As primarily a luxury STR buyer's broker and 20 year mortgage broker I can testify the importance of a reliable and experienced strategic mortgage partner. 

Which is more rent reliable, best growing, both for cash flow and long term appreciation?

If you're selling to flipper and the contractor isn't part of that, not sure it will be possible to get a reliable person. 

If you're seeking a reliable income stream, consider checking out Cleveland OH.

I have seen quite a few CRE platforms (Loopnet, Reonomy, Crexi etc.) and all have horrible ratings with the Better Business Bureau.What does everyone here use as a reliable source of info to prospect and be able to do due diligence?

In addition to the workmanship, you want to work with someone who is good at managing time, people and his relationship with you, his client :-)    We are actually building out a network of approved contractors because one of the biggest pain points investors and landlords face in Philly is finding reliable solutions.