I get to Manila 2-3 times per year and alway stay at the Renaissance. I like the hotel and I like the location next to three malls. I did not like the long ride to the airport when the traffic was bad.
I was looking forward to the opening of the new Marriott, intending to spend my last night there closer to the airport, and avoiding the heavy traffic.
For me this turns out to be a "win one and lose one." I am not sure that there is much to do around the new hotel but I will give it a try, at least when I am departing. I regret that both will not be available.