Experience in using COSMIC (FFP)

The COSMIC functional sizing model, founded in 1998 under Common Software Measurement International Consortium (COSMIC), is the next generation of functional sizing model that is not only convenient for business applications (like FPA or MkII), but also for real time software sizing (like telco or avionics software). It was formerly known as COSMIC-FFP for full function points.
Is there any experience in using this method and especially any experience in relation to first generation functional sizing methods like FPA or MkII?