Should I upgrade Mac OS 10.6.8 to El Capitan on Macbook Air 2010? I have the Macbook Air 11' late 2010 with Core 2 Duo and 2 GB RAM. I decided to install XCode 7, but it requires Mac OS 10.11 El Capitan. So, should I upgrade OSX on my 5-yearold macbook air? I worry about work speed.
I'm posting this answer from a late 2010 11" MacBook Air running El Capitan, and I have no performance issues. It runs very well. But this machine has 4GB of RAM, not 2GB, and that might make a difference.

Remember that 10.6.8 has not received security updates for years now, and will be full of unpatched vulnerabilities. It is a risk to keep running it.