If you do a search on the Starwood board, you can learn a lot about it. Basically, when you look at the Westin hotel, Club Regina is on the left and Grand is on the right. We stayed at Club Regina two years ago and toured Grand as my business partner had recently purchased there. The finished units were nothing short of magnificent. The pool area was to die for. The finished units all were "ocean front." The units to be built, that my partner purchased, were ocean view and were facing El Dorado golf course.
Then nothing happened. Finally notices went out that Starwood had taken over the unfinished part of the resort. But there are still no promises on when this will, indeed, be ready for occupancy and he is frustrated beyond words. Meanwhile, I have heard that things have gone a tad downhill - they closed the restaurant that was adjacent to the pool that was open for breakfast and lunch. Not the biggest deal for a guest as you can always walk over to the hotel.
Be warned the beach is only for looking at and not for swimming - it is so rough then don't even have lifeguards, and it is a downhill jaunt to get to the beach.
All that said, I would take the trade in a heartbeat. Cabo is beautiful and the units we saw two years ago were top notch. Enjoy.