There are two sides to this (product specialist - sales person / service specialist - Genius Bar help). I started off as a product specialist and really liked it because of my overall liking for the company, I really liked the products and enjoyed sharing a lot of their features with other people. I also liked that we did not make commission, you are compensated a much higher than average hourly rate, and this made it easy to suggest products you truly thought the customer would like, not just trying to sell higher priced items.
As for the service specialist, I really liked the freedom I had and the ability to help someone on my own. When people came in for issues I was the one who made them leave happy. It was a very satisfying role and I learned a lot with all the training.
The negatives are similar in both roles - any Apple Store is EXTREMELY busy. After a full shift, it takes a lot out of you and you are tired, you are expected to be upbeat and excited the entire time and it can drain on you sometimes. The biggest downside of the service specialist were obviously the angry customers. Phone’s are peoples lively hood and often times they treat these devices as life or death. Sometimes they can be extremely unreasonable.
I liked the ability to help people in their time of need and providing a customer experience that would make Apple customers excited about their devices and the services that came with them. The only dislike that I had was balancing a difficult school schedule with a 20 hour work week that was very involved and required a lot of mental focus and energy.