Gili snorkling was good, but we found the Gilies in general to be a bit overrun these days. maybe we didn't have the best day weather-wise when we went, but i found the water to be a bit choppy for pleasant snorkling. We had a much better experience/snorkling at Gili Nanggu (and the surrounding islands) in the south of Lombok. Less ppl, more fish/coral, clearer and calmer waters.
As for the St Regis Maldives, the coral is def coming back (esp outside of the OW Sunset villas), but will prob take a few years to recover from the construction of the place. The fish/aquamarine life is still pretty good though; we found an abundance of interesting fish/reef sharks/sea turtles right outside the villa, which surpassed my expectations based on reviews on this thread. I would say if you are looking for perfectly healthy coral, the reefs around the property prob aren't going to do for you, but you'll see a great variety of fish and you can always take one of the coral garden trips (or give the reefs a few years to recover)