I've stayed at the Hyatt OC a few times and the Diamond breakfast is good, rooms are ok, and having access to the Disneyland shuttle is nice, though it can get crowded. The new Hyatt House is much closer to Disneyland and walkable to the main gate, so depending on the age of the kids is something to consider. I've stayed at the Hyatt Place also, but there is no shuttle offered and walking distance is a little further than the new Hyatt House.

Based on my experience waiting for the shuttle in the morning at the Hyatt OC is bearable, but it will fill up fast so get in line early. Then again when leaving Disneyland, the shuttle line be very long and can add some considerable time to get back to the hotel. With younger children/toddlers this can be hard and you'd likely be able to walk back to the new Hyatt House way before you'd even get on the shuttle back to the Hyatt OC.