Sharing a mouse and keyboard between computers

I wanted to share a mouse and keyboard between two computers today. It happens to be between two Windows PCs, so I tried out Microsoft's Mouse Without Borders, instead of my usual Synergy (or US224 USB Sharing Device).

 I like it. It's easy to install, and has the settings I want.

• Benefits over Synergy: It's free (Synergy you need to compile from source, or pay for). 
• Benefits over my USB Sharing Device: Sharing Device takes several seconds to switch computers, Mouse Without Borders does not. 
• Downside to Mouse Without Borders: Windows only.