I can cast and double haul with either hand. I don't have the same distance ability nor can I cast some of the specialty casts such as a Curve Cast as well with either hand, but I have found the ability to be useful when fishing. I don't do it very often, but there are some situations where having the option to switch hands can be very beneficial.

The ability to cast with either hand is also a very valuable tool for any casting instructor to have available.