TaxGuyBill...I was with ATX for a significant number of years...back to the days it was known as Saber.  So I estimate in the 25+ year range.  The program treated me well, generally speaking.  Over the past several years, there was a lack of support and pricing continued to increase.  (I know, I've read the same can be said with Pro Series). I also found it starting taking forever to complete a return...even the most basic.  I don't know that was specifically due to the program or the added IRS requirements, but it did take long 

A couple things that really impacted me was the fact they did not include "advanced calculations" with their mid-tear packages.  I subscribed to ATX Max which provided me with unlimited federal and state returns, business and personal.  They did away with their 1040 package which provided unlimited personal federal and state returns.  99% of my business are personal returns.  Neither of those packages included the calculations that automatically provided credit for taxes paid to other jurisdictions or optimized education credits.  You needed to compute those manually.  I have a moderate number of clients who require both of those calculations.  Not a huge deal, but I felt the program should provide that...especially when their top tier programs do.  To purchase that functionality cost about $550.  In addition, there was a charge for their portal of $500.  Pro Series offered both of these ATX addon's as part of their package price.  I subscribed to Choice 200 Bundle.  

I've downloaded the Pro Series 2020 package and I'm acclimating to it.   It is similar to the ATX format (form based) but I know It will take me some time to get comfortable with Pro Series.  I did research it a bit and I know there have been many concerns voiced about PS recently.  I'm hopeful it's an upgrade over ATX.  Time will tell.