I vote for Xtabi too!
I have stayed at both places. I stayed in the garden rooms at SamSara and I have stayed in the Superior rooms at Xtabi
My first trip ever was at Samsara but I have stayed at Xtabi 3 times now, so my vote is for Xtabi, it is just one of my favorite places, the view, the staff are friends, the drinks are delicious (*Donovan makes the best dirty banana I have ever had) The food is much better IMO, the french toast, I dream about
That view! The cliffs.....to be honest Xtabi is like a second home for us, even when we stay elsewhere we still spend time at Xtabi.