Last year was my first MACNA and I enjoyed it a lot. I found that it really invigorated my interest in the hobby. One of the things that I really liked about it was the social aspect. The trade show itself is awesome, but the stuff that goes on every night afterwards is really enjoyable as well.
If you're really hard-core into the hobby, I think attending MACNA is a must. If you're more of a casual reefer (like me) then you just need to take a look at everything MACNA has to offer and decide for yourself. Take a look at the schedule on the website. It's not entirely complete yet, but it's starting to solidify.
If MACNA is within driving range for you, I'd strongly consider attending as it doesn't come to this neck of the woods very often.
Hope that helps.