I don't know when I actually switched to the UK method, although it was WELL before I moved here or even had the faintest idea of living here. Maybe I'm a little posh, who knows. I think it would be too bothersome to constantly switch back and forth, especially whilst eating a large steak. (Side note, it's considered bad manners to cut the whole steak into bits all at once unless you're a child)
But one thing that really irks me is the way some folks over here hold their knife as if it's a pencil as opposed to handle in the palm and first finger on top. Now, if you're going to go all out and insist on holding your cutlery properly and in the right hands, then by God certainly do so!