Hi Mike,
We use Vanquish. Its very good. We have tried many others and all seem to be very similar.
It may be your technique.
1. How long do you leave the chemical to soak in and work?
2. Do you pre heat the oven to 40 degrees while the chemical is soaking?
As for breaking blades.... mmmm? That's either bad quality blades or your pressing to hard which you should not be doing as you could damage the surface.
regards
Dave