Share your experience!
Chromecast require Android 4.4.2 and above
https://support.google.com/chromecast/answer/6059461?hl=en
as for lag, it's directly proportional to your wifi intenert speed.
http://support.sonymobile.com/global-en/xperiasp/software/
You may already have the latest software, depending on the date of purchase. Software updates are released at different times depending on operator and/or country. Therefore, we cannot give you an exact date for when a specific update will be available for your device.
Android version: Android 4.3 (Jelly Bean)
Latest available software: 12.1.A.1.205
Release started: 2014-06-10
You need an active internet connection for Chromecast to work
Let me test it, but keep in mind that your Xperia SP won't work
CC works just fine with youtube