Thanks for posting this. It was the first time I saw it. I'm going to try this next week. I did read all the T&Cs. It is pretty clear that old SPG brands will not get the bonus plus a handful of other Marriott hotels. I cancelled my two night stay at a Sheraton in SAT and booked one night at a Res Inn and one night at a TownePlace. Hope it posts okay. I'm lifetime Platinum Premier Elite (w/ Ambassador right now), so technically not Gold or Platinum right now, but I'm guessing the extra 500 miles should post anyway.
In making this change I will be giving up 3000 Marriott points (MegaBonus 2K bonus for 2 night stays + 1K for a new brand) plus I'm guessing about 1800 difference as half points staying at a RI and SHS (factoring in all CC bonus'). 5800 points total. I'll choose points at these two hotels for arrival gift (vs breakfast at the Sheraton) so I gain 1K back. I will also gain 2K total for the mega bonus for two new brands and checkoff the long term props I won't normally stay at. So Net loss is only about 2800 marriott points, but I should gain 3K UA miles. I'd say that is a great tradeoff.