Dh and i were just at the Renaissance in late march. Our first trip to Aruba, but certainly won't be our last! We both loved it. Loved the Renaissance, loved the private island.
I think the Renaissance Casino seemed a little less crowded than the Crystal Casino. ALso yes, the Crystal Casino seemed to have more locals. I do have to say I NEVER felt unsafe on that island.
And yes, there is topless sunbathing on Renaissance Island on "Flamingo Cove" or the adult side, though some parents did bring their kids over to see the flamingos and feed them. That was FUN!!
We also went to De Palm
for a few hours via one of those kayak excursions and there was one lady topless there. BTW, the kayak trip to De Palm was amazing and fun, but the trip back with the wind coming right at you was quite a challenge! I don't think i could have done it had i not been kayaking before and stengthened my arms!