The software and support for AD is superior. I've tried a few other types of programming environment, but it just doesn't compare to DirectSoft5.
I've recommended AD to a few other engineers I know in real life, and they are universally impressed - the stage blocks alone are worth the price of admission. Add to that free basic programming (I had to buy the retail version due to the size), very low pricing, and no proprietary cables, and you end up with a winning product.