Their outlet mall isn't really cheap compared to their US counterparts, but definitely more things to look at compared to JPO.
For me, I would feel that there's no particular dimsum place that any tourist die die should try. If you want to join in the hype, can go Tim Ho Wan. One Michelin star dimsum with cheap price. I've never been there to eat despite the hype because there have been many reviews that not everything is nice. The queue would always be long in the morning, with you having to wait one or two hours to be seated. They will give you a number and you can go walk around before heading back to the shop.
The queue already puts me off. I'll rather go to some local laid back dimsum place with old ah peks and ah maps reading newspaper while having their breakfast.
Almost all their dim sum shops or yum cha restaurants have their hits and misses, like this restaurant has fantastic siew mai, but that shop's har gow is better, etc, so its really up to you to explore around and try bits of everything everywhere if you think it looks good to you.
If you are staying in the Kowloon side, I recommend you try the Nathan congee and noodles shop at least once. At Saigon street, just right opposite Novotel Nathan's entrance. Their congee and you tiao damm nice...