>>11 I don't think either one is superior or inferior. Each one has its own function. If you want customization you buy a PC. If you want something that is simple enough for a child then you buy a Mac. If you want something for programming or data management then Windows or Linux will be your choice. If you want something for digital art of literally every kind, then Mac OS is the way to go. And so on.
As for the tablet market, you pay for what features you want. Personally I think the iPad has more features than its competitors and that will bring up its popularity. Same goes for the iPod line in comparison to other MP3 Players. However, I don't care for those features so I would go for the cheaper options, hands down.