Wow, that's pretty wild that your existing sink came out easily. I pretty much had to jack hammer ours out, and destroy the old sink in the process. Must have been a different factory person installing them on our boats.
I guess the number of basins must be one of those deep-seeded personal preferences, because we love our new big, single basin sink, and would not want to switch back to 2 small basins. Everything we've got: pots, pans, and big fish, all fit into it just fine. It's also got one of those removable wire grids on the bottom. I'd never used those before, and I thought I would probably just throw that away, but we love that too. It lets you have things sitting in the sink (on the grid), but not getting all sloshed into the drain water you're creating from other things. We often use half the sink as a drying basin while we are washing dishes in the other half.
The sink is a super heavy gauge/thick stainless material. I can't remember the species of stainless.
My only dislike is the bottom is flat and if the boat is listing at all, water can puddle in the bottom. I hadn't really thought about that, but I also didn't see any with sloped bottoms that had these other characteristics. First world problems, and somehow we manage to continue on with our lives.
Our other controversial choice is we used Corian on the counter where the refrigerator is. We really like that and it was not super difficult to work with. I don't think the weight makes that much difference on a 18k pound boat, and it's down low near the water line. I can't remember exactly how much that piece weighed, but my guess is something like 30-40 pounds.
We (so far) have kept the old formica on the counter where the sink is. It doesn't bother us that the counters look slightly different and I don't think most people would notice it unless they were scrutinizing. And if they are scrutinizing, there are plenty of other things for them to catch!
Based on your thread title, I think you're hoping to see photos of peoples Galleys. I can't remember which photos I've posted on the forum, so here are some (probably redundant) photos ...
Corian counter without any trim installed yet.