Hmm... How did this shift from a discussion of which comic reader we use to a flamey referendum on apple vs. windows? (I use a mac at home specifically because I use one at work in the art department. It's what I'm used to, no more no less. I know how to use a windows machine and could flip to one in a heartbeat if the price is right or if there was any real reason to. IMO, the whole apple vs. windows controversy is fake, fanned by people who have nothing better to do.)
Anyway, to answer your question, I use Comical on a mac. The only complaint I have about it is that it is slightly unstable, and will crash a time or two per session, with large files especially. The upside of that is that it's a very lightweight application and reopens after it crashes in just a second or two. The thing I like about it is that there's no floating watermark on the pages like there is with some readers I've seen. And it has nice features, like "view pages as a spread", which is like having the comic right there when you have a 24" monitor.