I also use Tax Tools https://www.taxtools.com/products_tt.aspx and an add on to Lacerte or ProSeries for maintaining source documents and copies of returns known as DMS. 

I am really old school with computers predating Windows and even DOS. I learned FORTRAN on a mainframe with punch cards and my first Lacerte program was run on a KayPro 10, which I still have. https://en.wikipedia.org/wiki/Kaypro

I believe the biggest screen you can get is a real plus to using PTO, regardless of the type of computer you use. Navigation is (in my mind) quite difficult.