I know a lot of folks are having issues with the download, etc. but I just wanted to say that I'm really happy with the Mavericks upgrade. Quick backstory -- I was so unhappy with ML upgrade (upgraded from SL, skipping Lion) on my 09MBP, that I was thinking of upgrading to a new laptop. Someone convinced me to instead add an SSD for boot. That helped a lot, but it still wasn't great. Mavericks has really helped. Performance feels really snappy the last 16 hours or however long I've been running it (and I've been hammering away since I upgraded, save my 6 1/2 hours of shuteye last night). I did, however, have to run diskutility from my recovery partition, as I was having some kind of file permissions issue. The upgrade took a while to download but went very smooth to the SSD. The SSD is only about 25% full, if that matters at all. The system feels VERY responsive. For the record, this is a 2.26C2D, Nvidia 9400GM, 8GB RAM with the SSD in the optical bay. Hope you get the same goodness and joy!