If your kids love legos then yes it's worth a trip. My 5 year old thinks it is the most wonderful place ever created. It's a theme park, mostly all the rids are geared toward kids under 12 so perfect for your ages - from a few roller coaster, to more mild rides, they have things that cater to different tastes of kids. My 5 and almost 4 year old love it. There is a great mix of rides and activities. There is an area where they can design and build their own hero factory creation, they can also build their own car and race it on various tracks. Each themed section has a play area so if a kid doesn't want to do a particular ride, there is an area to keep them amused while you wait for the others to get off rides (some areas are for younger kids, but there are 2 playground climbing areas that would be good for your aged children). There is a show, though we have not seen it. Also depending on the time Of year you go they do have some Special activities around the holidays. It has not been very crowded when we have gone (which is a nice break from Disney). You could spend the whole day there, but also get a good experience going for 4 or 5 hours.
Hope this helps.