I've used both for work; there are benefits to both but I would go with the AR500. The only real benefits that I've seen to the ceramic is that the newer models are getting lighter with each generation and you will have less spalling from high speed projectiles due to the kevlar lining. On the other hand, the steel plates can be quite heavy depending on size (coverage) but easier to conceal under a loose button up shirt or other layer and will not degrade due to rough treatment like the ceramics manufacturers warn against.