I'm a Mac user since my fathers first computer, a Mac LC III. I never switched and stayed faithful with Apple, and I can tell you, there were times, you were really a freak, because of using a mac. In our days you're a freak if you don't have any Apple product. Most people I knew while being young were using PCs. I was not able to play all these great games. I used most of my computer time to checkout how things worked. I was going through all this Mac OS 9 horror and tried to work with every Mac OS X release, until they got it working with OS X 10.3.
So, I'm one of these people knowing the Mac system quite well, and yes, there were many people switching to Mac, I can tell you. You could call me Mac evangelist. I definitly like the approach and ideas behind the Apple Os. It's about making complex things easy and nice to use. I definitly learned a lot from Apple for being a web dev. And, of course, Apple was and is changing how we use the internet. Right now, we use it diretly with our fingers on small devices.
So, yes I do Mac support. For example, I support MAPP-Empowerment GmbH to organize their daily business. We use Mac OS X Server with MacMini and mobile MacBook clients. iCal server calendar is synced to some iPhones over the air or a VPN Connection. Using mobile user accounts enables some team workers to work from home office. Most team members are young, female and have family with young kids. It's great to help with technical solutions to find flexible ways to enable your team members to work on stuff. So Mac OS helped a lot to get a small business running. It mostly runs smoothly and administration can be done remotly by screen sharing.
So thinking about a Mac setup for a small StartUp is not a bad idea. You will have more money and time to spend on things you want to do. In case of MAPP-Empowerment GmbH: helping children through working with their parents. And I think every minute is worth it.
If you need help for planning/setting up a Mac Server environment for a (perhaps really interesting?) project/StartUp, don't hesitate to contact me!