The interface looks pretty user friendly and comprehensive.

Not only would they have to maintain a web interface, but they'd have to maintain an Android app AND an iPhone app.

I had to play around with the interface a little to learn it, but everything was very straightforward.

But, because it is not catered directly to RE, there is more in there than you may need, and/or the user interface may not be as streamlined.You can find many many how-to's to optimize QB for rental properties, like this thread https://www.biggerpockets.com/forums/52/topics/590160-how-to-setup-quickbooks-for-personal-rental-portfolio

However, I visited the site and the user interface looks like it hasn't been updated since 2004.

It has a pretty modern user interface which works well with my tenant demographic, mostly young professionals.

They have a really cool interface for taking care of maintenance issues that I believe works well for your A and B class properties. 

They will also interface with the city planner of the local municipality in the local area in which they are building.

Biggest issue with booking.com was that I really felt their interface was terrible and took too long for a property to go live.

You do have to be comfortable working directly with tenants, doing showings and working out maintenance issues but, it's much better than it was.I also use a google forms web form interface to a spreadsheet to collect preliminary information for 1st level pre-screening and that works great.