I installed Windows 10 over Windows 7 two weeks ago.
 
First I wrote down the following:
How long Windows 7 takes to boot: 50 seconds
How long Sonar takes to start: 7 seconds first time, 4 seconds subsequent.
 
After installing Windows 10, a windows boot takes 35 seconds to when the desktop displays. The wait cursor keeps turning and stuff is still loading on the bar at the bottom. After 50 seconds the cursor turns from wait to normal.
 
Sonar start times have remained identical.