Hi Apologies if this has already been covered. I have a MBP that I bought in Nov 2009 and over the years it has been upgraded to each major release. I got halfway through re-installing SL (original disc) a few weeks ago and got bored, so the partition has been erased but no OS installed. What's the best option? Install SL and upgrade to Yosemite OR install SL, create bootable disk with Yosemite and go clean install?