This gets a 6-Fair. Besides the recycled jokes from the movie, the other main thing that bothers me about the attraction is the horse chase scene, in which pneumatic controls on your seat give the sensation of galloping. Too bad those pneumatics are extremely loud, and not to mention jerky, making a relatively new attraction seem old and cheap.
That said, you'll just have to wait to see if (okay, who am I fooling?) where PhilharMagic makes the field. :-)
I will give credit to the preshow and Donkey's Photo Finish which is very interactive and funny!
There's not really anything too unique about the attraction apart from it's moving seats, which as Josh mentioned are extremely jerky.
I bought Shrek 3-D on DVD, which is essentially the 4-D attraction you can enjoy from the comfort of your own home. I'd much rather put that in the DVD player every now and again than wait in line for the attraction, especially when you consider just how long the line can get.