Considering that Cambam Plus and Cut 2D both cost $150, for ease of use I would lean towards Cut 2D. Mach 3 is $175 on the Artsoft website, so you only save $10 if you bundle Cambam Plus and Mach 3 (which is not much of a discount).
Watch the tutorial videos and download the PDF tutorials and you will see it's not that hard to use:
Getting Started with Cut2D
You can use the free Draftsight program to make the 2D DXFs for your CAM program of choice.
One benefit that Cambam has is that it can import a 3D STL file. If you are using a 3D program then that could be a plus.
Mach 3, Cut 2D, and Cambam all have demo versions. Mach 3 without a license is limited to about 500 lines, Cambam gives you 40 fully functional sessions, and Cut 2D will let you cut sample files. Make some g-code then run Mach 3, you don't even need to have a CNC machine to test it out. I have my preference, but the best thing to do would be to give all of these a test run and see which is best for you.