ICloud On Mac :: Drive Is Not Uploading Files

I recently purchased a MacBook Air to use as a travel computer and wanted to share a few things between my desktop and the new Air.  I had considered using DropBox, but figured I'd spring for iCloud Drive instead since it's part of the "eco-system"... 

Trouble is, the files I want to upload to iCloud Drive don't seem to be uploading.  Maybe I don't understand how iCloud Drive works, but I was under the impression that it was similar to DropBox and that I could upload any type of file.  I have two encrypted disk images that contain all of my PDF receipts, tax info, etc.  I want to store both of these on iCloud Drive.  I also use MacGPS Pro for mapping and wanted to store the two map folders.  The map files are all .PICT and there's another folder containing .IEM files (whatever those are).  Neither the disk images, nor these two map folders, seem to be uploading.  A few of the PICT files uploaded, then it just stopped and hasn't worked since. 

Also, I can't find any way to see whether a file has been uploaded, is waiting to upload, etc.  DropBox is far more intuitive in that respect.  Is this information hidden somewhere for iCloud Drive?  Or does Apple just think we don't need to know it?  I look at iCloud Drive on my desktop Mac and I see all of the files I expect to be there.  But then I look online or on the Air and realize that virtually none of them exist in the cloud.  Very counter-intutive. 

Does iCloud Drive not work the way I think it does?  Or is iCloud Drive another half-baked cloud storage solution like iDisk that I should drop for DropBox, which I know works?