They're OK, but not great. You need to spend a fair amount on a plotter to be able to deal with fine detail. They will be OK for big graphics, etc.
If you have a design, send it over and I'll take a look and give you my opinion on the 'cut-ability'
Failing that, I'd be happy to supply you with them... you can buy an awful lot of graphics for the cost of a machine, and you don't need to worry about the maintenance, vinyl stock, etc.