I was burned twice by Agoda on prepaid rooms this year. The first time, the hotel offered me a windowless closet instead of suite I paid for. The second time, the Agoda booking never made its way to the hotel and no rooms were available. Agoda did try its best to appease me after the fact, but a lot of time was wasted in the process (i.e. hotel hopping at midnight isn't cool). I have NOT encountered similar with any ctrip bookings yet.