Quote from @Chris Lo: Which platforms/websites do landlords use to find the rent rate, how long the rental properties have been on the market, and all the details about other rental properties?

There are many horror stories on collecting for damages from OTAs including a current thread on BP where guest left doors and windows open upon exit that resulted in frozen pipes.  

What if something changes with how that platform works?

Why do you put a window that low in the bathroom? 

My secret is I use the one-hour window to allow cancellation.

Also, SAAS platforms are supposed to include support and service (that's the last S), but the quality varies greatly from company to company. 

These platforms include RentRedi, Stessa, Avail, Innago, Apartments.com (formerly Cozy), and TenantCloud.Pretty much every platform mentioned contains the features you are going to need.

Has anyone bought from the platform?

I know Shopify typically is a more commerce base platform.

Paid platforms often offer additional features like market analytics, off-market property leads, and filters for investor-specific criteria, giving them a leg up over free options.Exactly, most platforms have to offset cost somewhere because of how expensive it is to keep the data up to date.