Hi Claus,

"Who uses and has some experience with CYGNAL's MCU C8051F00x?"

I do and I have :o). Do you have any specific questions or do you want to know my opinion or....?

My latest project has an 'F015 and I have used just about every available peripheral. I must say I'm really impressed both by the part and the technical support from Cygnal.
Personally I use the Raisonance system for development (both C and asm).

If you have any specific questions, I'll be glad to answer them.

Best regards,
Rob Klein