So let's say you have a lot of experience diving in cold water with low visibility. Well, how does that translate to diving in Cozumel? I'm not sure it does. It would be like saying that knowing how to play tennis makes you a good ping pong player.
In terms of diving, going from cold to tropical had no learning curve for us. Everything is delightfully easy from the lack of buoyancy swing to working gear in bare rather than gloved hands. Nothing I'd call a real skill change, just less need to use them. The flora and fauna are new but that will vary between destinations regardless of translation.
I have to admit that I was a little leery of being able to see so much life at such a great distance but I got over that.
If you have not been boat diving locally then that may be something new in a place like Cozumel. That's just an effect of the kinds of diving you choose in the respective locales. Once you go down, diving is diving.
Like many places the "if you can dive here you dive anywhere" mantra is spoken here in Maine too.
The inverse of going to cold water from warm is a challenge. I have had numerous warm water guests comment that cold water kicks it up a notch. If they were competent warm water divers that geared up appropriately they adapted readily. Those that chose to whine will probably fail to adapt.
Pete