Yep, no problems here, used EEO BOGOF's twice for global rate breaks.
I have read numerous postings about problems with the BOGOF but have had no problems whatsoever in the UK with these, all FD staff seem to be aware and second night is always correctly uncharged!
I dont know about USA but in the UK, not all hotels honour these BOGOF's and by the end of each award period the choices can be very limited, but the Plat line is very informative, so no problem. Apart from that, no complaints, a Marriott stay for less than the cost of a Travel Inn... Bargain!!
It does seem strange that these can only be booked by phone, I do all my Marriott stays online so using the Plat line is, for me, a bit of a bind!