Definitely worth it if your kids have an interest in Legos
We visited Southern California a few years ago when my son was 9. He is very much "into" Legos, and he wanted to visit Legoland more than Disneyland. He loved it and we thought it was fairly enjoyable. The rides are not all that memorable, but there are play areas set up where they can build something and then have it put on display. There are also plenty of places for parents to sit or have a rest, while the kids are building something. The best part of the visit was the area with all the iconic sites built out of legos (Taj Mahal, Sidney Opera House, Mt Rushmore ) and various US cities like New Orleans, San Francisco, Las Vegas, and New York also recreated. My son also enjoyed the absolutely *huge* lego store. Not sure it is a good value at full price, but if you have coupons (like you mentioned) I think it is a fun stop. Not to mention, it is close to San Diego and there are several really cool places to visit with kids in the vicinity. In fact, there is a Southern California pass (or it is called something like that) that has choices for the zoo and it seems like something else (maybe Seaworld?). I seem to recall that the other choices on the pass were more in the LA area.