Posting this in the hopes that it may help some.
Booked a 5 night stay using points pre-merger. Category was reduced post merger. Called (twice) to address this. Today I was refunded the points, plus a bit more for the hassle.
Both CSRs were very helpful. This morning's spoke about all the problems and changes. He did say it would be 'amazing' once all the bugs are worked out.
My only post-merger hanging chad is my missing 75 night annual choice benefit free night. It posted and then went away. I was told it is somewhere in cyberspace. They pushed this up the chain for further investigation.
Some what related to the merger -- my anniversary business MR Chase card only gave me a cert worth 25K instead of the 35K. I don't have the energy to pursue at this moment. Is it a Marriott fix or Chase? I'm fearful both entities will point fingers at the other.