Anyone still on Snow Leopard ?

So I've recently switched to Mac, having been given my dad's old MacBook Pro which was running Snow Leopard out of the box. I remember it was extremely speedy on SL and was an all round great machine. I have Mavericks running on it now and while it still is powerful and gets the job done, it really is starting to show it's age here and there.

So my question is, is anyone here still running Snow Leopard ? And if you are, how secure is it to be running it considering it's quite a few years old now ?

I also ask as there's one particular piece of software I have which runs on the PowerPC architecture and as I understand SL was the last release to have Rosetta support.

Any feedback would be appreciated, thanks !