Hi there, I also did Merch on my ICP last summer at the Emporium, Main Street USA. I have no other merch locations to compare it with, but from what I can gather, the expectation for the Emporium is higher than at other merch locations. It is the most popular in-park shopping experience and the second in the whole resort (first is World of Disney). Yes, the hours for the CP are crazy - anything around 40 hours is considered a good week, and I would have at least two 4am finishes per week. An 'early' shift for me would end around 10pm (and they were rare!) and I would often be scheduled 12+ hours.
BUT - I loved it. I loved the location, being at the heart of the action; welcoming people in the park and often, being one of the last cast members they see on their Disney vacation.
However, due to the business of the location, my hours were a lot more unsociable than merchies at other locations and we also had less time to perform 'magical moments' with guests and a lot less 'merchantaining' (essentially a guest interaction role) than other merch locations. I only got to do the 'wave' (waving to the guests as they enter) a couple of times on my program; but it was one of my favourite things to do from my program. Moreover, getting to see the 4th of July fireworks whilst at work was amazing!