Better flapper disk?

[lsloth]

I was flipping through this months Machinist Workshop and they had a little write up on some new grinder disks that looked kinda cool.
http://www.rex-cut.com/products/sigma_green_grinding_wheels.html
They appear to be a cross between a regular grinder wheel and a flapper disk. I love my flapper disks but they wear out pretty fast. These might be a better solution. Has anyone used them?

[MiniMog]

I use something similar but you need to be easy on them, they have a problem with breaking apart if you really lean on them.

Work well for what they were designed for though....