You can use the silhouette cameo with or without cutting mat,
If you need to cut a very small peice of vinyl use the mat, I tend to always use it anyway.
Only disadvantages with the roland is that you cant use offcuts like you can with the cameo. The cameo
cuts perfectly and I use hotflex vinyl and it is simply perfect, the blade
Lasts for an extremely long time, for hotflex I have it set on blade cut number 1 speed 8 and thickness 12. Does what it says and does it well. Get one I guarantee you wont be disappointed.
For the money it has to be the best machine out there. Nothing I have heard of comes close.