In our experience thus far, many people who have upgraded to Windows 10 have had experienced poor performance and, in some cases, major problems.
We are noticing that computers with Inuit products (Quickbooks, Quicken, Will Maker, Turbo Tax, etc.) are experiencing issues with the upgrade. Inuit has stated publicly that the will NOT support Windows 10 on any of their products except for the 2016 versions. Many of our clients have been forced to upgrade to newer versions costing them hundreds of extra dollars. Other products that we have notice include Adobe products and Microsoft Office products.