Henryville:
You may want to think more broadly about the DS. I was in Ft. Lauderdale last February (not what I consider a cold destination,) and I wore my DUI CF200 and 200g undergarment the whole week. I honestly believe that compared with my 5mm full suit wearing trip mates, I was by far the most comfortable. I think you can wear one on the North American Pacific coast year round. Also, a drysuit is recommended in general if you are using double cylinders.
I can't comment about wearing a drysuit if Florida, but if the water temp was below 75, I could easily see myself wearing mine there. I would definitely take my drysuit to Hawaii if I was going there in late winter too.
I can comment about the PNW. Wearing a drysuit is the only possible way I can dive here. I also had to add drygloves to dive BC comfortably, but it is
definitely worth it. In fact, last Feb. I spent 12 hours driving from Salem Oregon to Campbell River, British Columbia to go diving. I had a fantastic time, which a
Trip Report and a
Photo Gallery to share from the trip. Everyone on the trip was diving dry. The water temp was a pretty constant 45 f and I don't think you'll find anyone doing multiple dives wearing a wetsuit in water that cold.
In September I flew to Santa Barbra to dive the Channel Islands. It was great and the water was
warm, which of course is relative. Lower 60's, upper 50's might not be considered warm by some people.
So, obviously for me, getting a drysuit was a good choice because I live in a cold water part of the county and I like to dive more frequently than I can afford to fly to the warm water dive destinations.
I guess to answer your question I'd say yes. I do travel to cold water destinations
just for the diving. Having a drysuit makes the diving more enjoyable. I have enjoyed the diving in BC and California quite a bit and I actually prefer the diving there over Hawaii. There is just more variety, more color, and more excitement (at least for me) diving in the cold water.