Have read through this thread, TPG, and the T&C's of the various cards. Sounds like you can alternate Personal/MB Platinum and the Business Platinum every 12 months.
I have the PRG card that I plan on cancelling in February (when the annual fee hits) unless I get a good retention offer. Seems to be that if I want to start churning/alternating the Amex Plat, I should apply for the Business Plat first, and then alternate every 11-13 months. I looked up the Business Plat and it seems to have a 25k MR offer. Is that the best offer or are there better ones that come out periodically?
Also, if I open a Business Amex card, will that preserve my Personal MR balance? Will I be able to see my Business Amex card on my personal account?