I have an alienware m15x and m17x.

I sent my m15x in for repairs since I broke the charger pin inside the charger port.
This happened LAST YEAR FEBRUARY(2013) so we sent it back to the store I got it from, I only got it back this year and the store that I bought it from just gave me a new charger(all under warranty) and they still haven't fixed the port. It still charges anyway so that's fine.
But back to the topic;

I got it back now and I am not sure whether to Upgrade them to windows 8. Is it worth it?

Currently running on Windows 7.