divemed06 once bubbled...
Cold water and warm water diving are 2 totally different types of diving environments. Do you believe that being trained in cold water makes you a more skilled diver than being trained in warm water (tropics)?
There not really two different "types" of environs... their just two different temperatures, so one can't make an accurate distinction. Cold alone isn't that bad (i.e. diving cold in a quarry takes similar skills to diving warm off Cayman, just different thermal requirements).
On the other hand, different "types" of environs would be more like high current (Pompano, St. Lawrence, Pacific Northwest), big water way offshore (New Jersey, Florida Gulf, N.Carolina), High Viz (Cayman, Coz), Kelp Beds (California), Good vs Bad Viz, etc
These are examples of things that can be "combat multipliers". As a cold water barbarian, the cold vs warm isn't that much of a factor. In fact with the exception of Cayman or Coz, you could dive a drysuit in all of the other areas I mentioned (depending on time of year).
Now, if you want to compare the skills of the average diver that regularly dives Cold water with mediocre viz in fast currents vs someone that spends time diving off 7 mile beach in Cayman (warm water, great viz, minimal to zero current, then I think you've got yourself a poll question.
Also, once you get comfortable in one environment doesn't make you good in another. (i.e. Let's say you comfortable in the Great Lakes and go South to swallow your first mouthful of saltwater... how comfortable do you think you'll be?)
Bob