Final update,
after a very productive exchange via the redhat bug tracking system, it
turned out my BIOS was causing the problem. Flashed the latest version an
d
voila it works like a charm. (Samsung Q45 BIOS ST7 to version ST11)
Before that I could get it to boot with kernel options pci=nomsi acpi=
off
before the crashkernel and rhgb quiet removed.
Maybe someone will find this useful in the future and won't have to feel 
as
stupid as I do at the moment for not catching something as easy as this.

regards,

Matt