I think most left handed people can use there right hand better than right handed people can use there left, simply because there are a lot of things in life that don't really allow for people to be left handed.
There are still a few things I come across where being left handed is a disadvantage. One I found recently was hockey.
I know a left handed kid who gave up hockey as he also played golf. You can play golf left handed but not hockey. As he learnt to swing the left handed way (for golf), he found it harder to play hockey.