I was impressed by the pace at which they added reciprocal benefits for members, including the ability to status match and also transfer points between programs at a fair rate. (onemileatatime.boardingarea.com)
Once your accounts are linked you can easily transfer points between programs. (members.marriott.com)
Now that Marriott's acquisition has closed, and they're already letting you link accounts, match elite status, and move points between programs, there are fantastic arbitrage opportunities created. (viewfromthewing.boardingarea.com)