They certainly are.
Take a look at the ones sold by sites like hornig, touratech, boxer design, wunderlich for comparison purposes. Oem ones cost 330€ per set. The old k12s are using the newer version used at the K13S discs with less bolts and nuts, and no floating gaskets as the older design.
Ebay has some beutifull design brembo. Make certain if you get any aftermarket set that they are the floating type and include nuts, bolts.
Experiance only with trw made by lucas they were good and still are in use on the old k12s after 40.000 kms and 7 years.