People use them around here but I think it is more just for the sake of using them rather than because they are the most practical tool for the job (in most cases). The exception would be in the Potomac during the shad run if you are fishing from shore. There are only a handful of places that allow for an easy backcast and they are frequently taken, so having the two hander is useful in those situations. There are a couple places where you might fish for stripers where a two hander would be useful, especially if you are a right handed caster.
I personally wouldn't buy a two hander just to fish around here but they are all I use for steelhead fishing so by all means get one if you think that is something you will be into.
If you are going to go with a two-hander, Skagit heads and heavy tips are generally what you want to be thinking, at least for the Potomac itself. I use a 13 foot 7 weight when I do.