Hi!
I am very interested but it's not clear to me whether these are minus alpha releases or something intented for production...
I would say kfreebsd-i386 is roughly "unstable" as other ports are in "unstable". kfreebsd-amd64 is younger port and is slightly worse. Current status would be beta for kfreebsd-i386 and late alpha or early beta for kfreebsd-amd64. The easiest way is to evaluate is to just try, i.e. inside qemu. Petr