I have a Keencut Excalibur with both the razor blad and cutting wheel attachment. FWIW - the razor blade does a good job on 4mm coro, 3/16 foamboard and 3mm PVC. The cutting wheel does work decently on .040 aluminum and 3mm poly-metals but it takes a good bit of effort and sometimes the material can skew with all the force being applied.
Anyway, for me I swear by my DeWalt track saw. (Same as Festool) It does precise, clean cuts on PVC, MDO, HDU, light aluminum and 3mm/6mm poly-metal. So I tend to use it for that stuff and cut my foam and coro on the Keencut.