I just spent the weekend installing rockwool I got from:
http://www.insulationworld.com/
about $40.00US a bail compaired to 703 @ $100.00 for the same sq.ft.
It was easy to work with.
What I did:
1. Cut a piece of ply/chip board to 4x6ish
2. Take 2 18" pieces of 2x4 and use them to frame a corner of the big board to 2'x2'.
3. Make a slit cutting diagonal through this 2'x2 square you made on the corner of the big sheet.
4. add 2 clamps, a serated kitchen knife and a 5" 1x4 and you have a mineral wool cutting machine.
Use the framed corner for slicing the panels into 2'x2', and the diagonal when you need it for the corner.
Use the clamps and 1"x4" to "rip" the widths you need and to create a square for cutting length.
God I hope this makes some sense......
BTW: If mineral wool is difficult to work with, you're not doing it right.
Good luck!
D