We just got back last week from Grand Cayman and we stayed in a condo at Coconut Bay, right next to Turtle Reef, arguably the best shore diving on the island. The location was great! This was our 4th trip to GC and we don't bother to get on a boat there anymore. The shore diving is just as good and much cheaper too!
We dived at Sunset House but were very disappointed at the viz (30-40 feet max). We have dived there before with much better conditions so we're hoping this was a temporary, weather related condition.
Another fun shore dive is Eden Rock, though the coral is in terrible shape due to over-use, the caves & swim-thoughs are really fun, and there are places there where there are more fish than water! Tarpon galore as well.
I enjoyed the Dive Tech location at Lighthouse Point very much. We were surprised to find they've moved out of Turtle Reef, and are now just down the street, currently with just a kiosk, but with plans to build a small condo "resort" with a full dive shop. Dive Tech is also at Cobalt Coast, which is another great place to dive. They have a pretty good deal for shore diving and lunch for only $20/head. When you consider the diving costs $15 for tanks & weight that means lunch is only $5. Believe me with prices in Cayman, you can't even buy groceries that cheap to make your own lunch!
And then there is Sun Divers at Turtle Reef, downstairs from the Cracked Conch restaurant. This is a really fabulous place to dive. The mini-wall is so pretty and the deep wall is great too. Since we were staying right next door, Sun Divers let us take some tanks to our place for a night dive. We drifted from our place and exited at Sun Divers. I highly recommend that dive!
Well, it looks like you've already made reservations. I've heard nothing but good things about Turtle Nest, but it is a little bit out of the way for the shore diving in George Town and West Bay. If your reservations are still flexible, I highly recommend staying at Coconut Bay, though you are on your own for diving since there is no operation right there. But like I said, Sun Divers is right next door, and Dive Tech is in two locations, both less than 10 minutes away. We stayed in this unit (2 BR, 2 full baths):
Coconut Bay Getaway, Cayman Island Condo Rental which we found at
..VRBO® is Vacation Rentals by Owner® Vacation Homes Rentals by Owner and we were able to negotiate the asking price down quite a bit. There are other units available, with more rooms, surprisingly for only $3000/month. If you can find another group or family to take 2 week shifts, you'd be getting an amazing deal!
Have fun!