Hello Carl,
Great question!!! I recently read multiple reviews and watched hours and hours of different videos of multiple doodling programs before deciding to go with the Shapr3D program for the iPad. I used the free version for a while to see if I liked it and recently committed to the purchase which is $240.00 per year.
That written, try as best as you can to put together what you would like to achieve with the program and determine which is going to benefit you the best.
Economics certainly can drive that choice. I’m in an area where kids drink custom design coffee from Starbucks for $5.00 per cup. They might drink 5 of those in a day. $25 x 7 = $175 per week / $758 per month / $9,100 per year…
I remember seeing the bill for the programming department built for my company in the early 90’s … I could have purchased a moderate size home at the time for the amount of money put out. Pro Engineer was the programming system at the time. I never personally used it.
I see things as having drastically improved becoming available economically when it comes to computers and software so I’m no help there…
Here’s where I’m at … iPad - Shapr3D…
From what I’m seeing and reading, Fusion 360 is a good choice…
You know I’m Solidworks to the end… 
