Dear Casper,
thank you - I will come with wider reflection later now just short info that my experiences with use of both methods (ASAP and PRINCE2) are bad. You are right - ASAP is for vendor where PRINCE2 is for control of the project by customer. However implementing ERP by ASAP is some kind of commodity where in PRINCE you have to define a lot of project details and that makes first "reinventing the wheel" and - what worser - a lot of bad interferences since PRINCE2 has different construction. In my opinion that is very low sense in use of PRINCE2 for ASAP driven project.
You can find many interesting aspects in the discussion I joined several months ago:
http://www.linkedin.com/groups?search=&answerCategory=myans&gid=2775
Regards
Waldemar
