I just took a look at the actual text of the RCA/BDA prenup. It is quite horrid. (And that is aside from the halachic objections Rav Elyashev has to the very concept and theory of this type of prenup.)
A. It has the husband sign that he is agreeing to forgo Halacha (Jewish Law) in the case of divorce, and accept whatever secular law at the time says for the issues of divorce, even if they are in conflict with Torah Law. (i.e. Separation of assets.)
B. They agree to use the BDA, and no other Beis Din, for all divorce matters. The BDA is quite on the left-wing spectrum of Orthodoxy and is known to employ a feminist agenda and often eschew Jewish Law in favor of employing non-Jewish law.
C. It obligates the husband to pay her $150 per day, from the day his wife left his home (or forced him out of his home) for any reason. As long as they are not living together, he is obligated to pay $150 per day to her. (Actually it will be higher than $150 since it is indexed to increase with inflation, from the day of marriage, per the CPI.) She could simply wake up one morning and decide to separate, even if Halacha does not allow it or entitle her to a divorce, and he is immediately obligated to pay up or give her a Get.
Furthermore, the prenup makes no such provisions upon the wife should she refuse to accept a Get from him. She cannot be made to pay him any backbreaking daily monetary obligation should she illegitimately decide (even against the orders of the Beis Din) to refuse to accept the Get.