We travelled to Belfast on Saturday to visit W5 and I recommend it as a day-trip.
Passed Dublin Airport at 08:50 and was walking into Odyssey Centre at 10:30 - roads are great and getting better so the driving is no hardship.
£16.00 for 2 adults and 2 kids (5 & 3) and there was loads for them (and us) to do. Popped out at 12:30 for a good value lunch within the Odyssey complex and then back in to W5 until 2:30. We were all getting tired out at that stage and the volume of visitors was increasing all the time.
Home via Sainsburys Sprucefield and we all had a great day out.