Corky:
The interiors of the units vary in terms of condition. I own four weeks at the resort which I use personally or donate the use of to charitable auctions in my community. I was there in March, along with 2 guests. We all had two bedroom townhouses. My unit, oceanfront, had been re-done. On a scale of 1 to 10 in terms of condition I would rate it an 8. Newer kitchen cupboards, good appliances. The only thing I really didn't care for was the carpet, but there was nothing really wrong with it. I personally just would not carpet a unit on the beach.
One of the two poolside units had not been renovated in a while. It certainly showed in the kitchen cupboards. Having said that, my guest said that "this was the best family holiday that we have ever had". Indeed last year when I was there I had a poolside one bedroom, the VERY WORST location in the complex, yet I had a GREAT TIME.
If you want to go to Cayman I cannot see how you can go wrong. Unless you are one of those "golden" individuals who can only accept the very best you will have a great time.
As far as the difference between Tortuga and the Grand next door there is no meaningful difference in my opinion, except for the fact that some of the units at Tortuga do not have a dishwasher (but the unit I stayed in most recently at Tortuga did have one). This is hardly a hardship. As well, the Grand unit will have a washer-dryer and the Tortuga unit will not. As in all likelihood you will be in your bathing suit for a week I do not see this as a major drawback either.
So if you are not a golden boy I would confirm and have a great holiday.