I've made several reservations this week, both from my laptop and from the hotel's business center. The new website has appeared, disappeared and reappeared over and over. One time it was there in the morning and a few hours later it was gone when I went back to it.
One thing I have noticed is that the new website requires the credit card CVV code to make a reservation. Kind of a PITA for me since I have my SPG AMEX number memorized, but now I have to pull the card out anyway to look up the CVV number.
The new website seems different, not better.