I could go on for ages about OS X's many flaws, but I'll be brief. Over a year after making the transition, I still find the dock awkward to use: I'm never happy with where it sits; I find the magnification feature serves no useful purpose; and the Dock hiding feature doesn't work too well if you prefer to use a pen and tablet. Then there are the gaudy icons; an inevitable result of the increasing power of computers. When Susan Kare designed the original Mac icons, she had to produce meaningful visual representations of application tools and folders with only the minimum of resources available to her. When you are limited in this way, sometimes the best design decisions are made (think 5k). This is why Kare's designs are so magnificent; they are direct and they communicate a great deal only using a few pixels. Now however, computer power is such that this limitation is gone. The designers at Apple have come up with a set of pictographs which, love ‘em or loath ‘em, you're stuck with, unless of course you make use of Candybar or other icon management software.
Now that the negatives have been dealt with, I'd like to explain why I haven't looked back since I started using OS X. Firstly, in my experience, OS X is stable; on the occassion that an application does crash, it doesn't bring the whole system down with it. I can leave documents open and multitask secure in the knowledge that I'm not going to lose anything. Secondly, there's some great software being produced for it: Navigator is a pleasure to use and is now my default browser; NetNewsWire is a lovely lightweight app I use for reading what's new at my favourite blogs and news sources; then there's software like BBEdit, Adium, Transmit and Tex-Edit which are well made and easy to use. All these things have one thing in common: they are apps I use alongside the web, whether I'm consuming it or creating things for it, and this is where I'd like to bring in my third point. Where the Mac was once a desktop publishing and design-for-print machine, it is now a true web machine. Admittedly - and this is going to sound odd after that last sentence - the web browsing experience on the Mac isn't great; Explorer remains buggy and occassionally mis-renders pages and Navigator, while it renders beautifully, is far from complete. However, as a web designer, OS X has given me a huge boost in my knowledge about the technologies that drive the web, mainly because it has a web server pre-installed. Apache, MySQL and PHP; I knew nothing about these technologies before I started to use OS X. Now I have them set up and running on my machine at home; I can learn and experiment with dynamic web content without being online, which is a great help if you're on a dial-up connection. So this is the main reason I'd never go back to using OS9; OS X has widened my horizons about what is possible with the web.
So, I hope Zeldman perseveres with OS X. While its user inferface may not be as transparent and generally as cool as its predecessor, it is a better operating system. It just needs time.