Ventajas
Personally, the best reason for me to work at Apple was that you get to be a part of something really fantastic. People are changing the way they run their lives, whether business, personal, or both. And often, you get to see things become easier for them by switching to a superior Operating System. Additionally, you get to meet people who share similar interests as you, especially in certain fields. (For example, this might just be that you enjoy using a Mac, but you also get to talk to a lot of people who use software that's Mac-only, like those many Music or Film production applications.) This is also a really great job for those who enjoy teaching. A lot of what you do there isn't as much selling as it is answering questions and solving problems. That can be really fun - especially if you can show them an easier way to accomplish something or fix a problem that they thought unfixable. When you do sell, it's not like other establishments where the pressure's on or you're dependent on commission. Also, the products kind of sell themselves. There's rarely a situation where you feel like you have to sell something you don't believe in. There's something right for everyone and part of the fun is helping someone find the right fit.
Desventajas
If your management team isn't competent or trusting, just like any job, it can become difficult. At Apple, there's a lot of self-motivation. Meaning, for things to work well, you need to be able to take initiative. However, if the manager seems like he or she might be a micro-manager, then it doesn't go as smoothly as it might at another Apple Retail Store. Another downside of working at an Apple Retail Store is that it is a great job and a lot of people want to work there. Unfortunately, with such popularity comes a few bad apples (no pun intended) who can ruin the fun for others. There's been a lot of recent limitations instituted against Mac Specialists and it takes away from the atmosphere of trust. My main recommendation to an interested Mac Specialist would be to check out how the other employees are doing to see if that exciting and fun atmosphere still exists.