Is Webmastering on a Mac really that different from doing the same on a PC? I've been a Mac Webmaster for my entire 6 years online and have not actually tried it on a Win machine, although one sits right beside me here for use when I get PC only attachments or downloads.
I've often seen that little "Made on a Mac" logo on sites and wondered why that mattered. Is it due to Mac specific editing tools or just pride of ownership of the best computer? ;-)
No difference really. I've always preferred the Mac because it feels like Windows fights back. But maybe a long-time Windows user would say the same about a Mac. As long as you have the tools, it's really a personal preference.
One gotcha, though, is the default difference in gamma. Out of the box the Mac's display will be brighter in certain color ranges due to the difference in gamma. What looks like (for example) a charcoal grey or say a dark purple on the Mac could come out looking jet black on the PC. So I just have my Macs use the same gamma as PCs to get around it.
We have both Mac-based and PC-based designers/developers here, and I can't recall any serious case of not being able to share files -- the Photoshop files we create are fine on either platform, for example. So our experience has been that there's not much difference ... aside from pride in the machine. :)