The new CR cuts up to 0.3mm thick cardstock just fine just like the older version, but the new model actually has a bit more cutting power behind it. They both can sometimes cut a bit thicker material if you have them cut round two or three times. For what most people want it does the job, and does it well. But it's not a heavy duty machine and doesn't claim to be - the specification will tell you what its capabilities are; if you want a cutter with a bit more oomph then you need to look at the Pro instead.
I think it's very important, whatever machine brand or model that you are looking at, to know what you want to do with it, and check through the specifications and any and all documentation, information, etc that you can lay your hands on, and talk to the suppliers if necessary, to see whether it matches your requirements. That way you'll get what you want and not be disappointed...
I bought my Robo with the knowledge that it wouldn't cut as thick or as big as I wanted - but it served me very well until the Pro (which does exactly what I want) was available - and affordable for me.
Rosemary