HVAC Feedback appreciated -

So the installer has been working on my gad furnace/ AC install.
He brought an "Airtemp" yeah the one that was made by Chrysler YEARS ago. Now made by Nordyne that makes several names.

I hope this is a good unit. Any thoughts?

Also, I was kinda disappointed that he installed the Compressor on a PLASTIC pad on the outside of my house. He dug very little to "level" it, and through down some rough gravel.

I believe this should have be done on a cement pad or at least use pea gravel under the plastic pad and some sand.
Am I right?