I got this just over a year ago, so I thought it would be time for a review.
I got the 9-plate model although they do offer 7 - 8 plate models and 5 - 6 plate versions for women.
The build quality is very good, with good stitching of the component parts. The inner foam lining is quite thin - about 5mm, so I wouldn't expect too much of a cushioning effect. The plastic armor itself is hard, and the plates are aligned in such a manner that they would protect you from a penetration type injury and would help resist any backward bending forces.
There are some perforations in the lining to help with cooling. I've worn this in 80+ temps and have not found it uncomfortable. It fits nicely under my jacket and weighs about 2lbs. It's very comfortable when on the bike, and not too noticeable when walking around.
Word of warning: if your waist size is over 36", you would need to buy the belt extender as well. My waist size is 36 and it just fits. The 2 shoulder straps offer a decent rage of adjustability.
The armor is CE approved.
Here's a link to the factory website:
http://www.planet-knox.com/product.htm
Google will get you other reviews and dealers. Price seems to be around $180 right now.
Would I recommend it? Absolutely.