Had one for about about four years and it's still going strong. They may have changed the size/weight since I bought mine.
Plus
Carrying system is really good.
You can carry loads in it and can cover the straps to avoid them getting muddy
Great for padding out uneven landings
Landing is pretty good
Long lasting - I have it under my board so it's taken a shed load of small falls
minus
It weighs about a tonne, well about 12kg
I like it if I'm working something for a long time or doing a few problems in a small area. If I'm doing a circuit or it's a massive walk in I take something else.
Review here:
http://www.outdoorgearlab.com/Bouldering-Crash-Pad-Reviews/Mad-Rock-R3