For everyone playing the at home game, I'm on the phone with HHonors redeeming my points, QF3N's, R2D2's, and everything else for the 9 nights at the Conrad MLE.
While the agent sent off to NASA to calculate something I asked her about the whole pre-paid breakfast while my My Way was set for free brekkie. She said "yup. You negated your Diamond benefit by pre-paying for breakfast. The hotel did not have to provide you with a Diamond benefit."
As was mentioned up-thread, according to the language on Hilton.com that is not true. But, further validates my assertion that the HHonors program is way too complex and that even a call center "Diamond" agent doesn't understand the program.