Has anyone used Lakeshore's .500 diameter x .125 Corner radius variable flute endmill on their Tormach?

variable flute end mill for aluminum

I bought the standard helix (30 degree) 4 flute version a few years back and it chatters badly on all but the lightest cuts (no more than .030 DOC)
Wondering if the variable flute works well in aluminum and don't want to pay $60 to find out.