I almost bought the upgrade disc today, however on further thought and reading around here, i've gathered that people seem to have A LOT of problems with macbooks in general. Since i bought my computer used and it doesn't have apple care, i'm thinking the age old saying "if it ain't broke, don't fix it." Because i'd hate to upgrade then i start having wireless problems etc. Is it worth the upgrade? I do a lot of digital audio oriented stuff and i'd really like to upgrade simply because some virtual instruments and plug in's only work with 10.5 or above.