I took the plunge and upgraded from OSX 10.7 Snow Leopard directly to OSX 10.9 Mavericks (free from Apple!! WOO HOO!!) on my laptop. Yes, I made sure I had a backup first!!
So far, I’m happy with it, and it runs pretty smoothly. My laptop is a mid-2010 MBP 13″ that I’ve upgraded to 8GB RAM and 750GB “hybrid” drive – it has a 64GB SSD.
I noticed the system was a little sluggish at first, then I rebooted, repaired permissions, and rebooted another 6 times – this helps the HDD know to move the OS and startup apps into the SSD portion.
Have you tried it? What did you think?