Pokerstars have introduced Heads up Zoom tables which I'm really pleased about. I used to play a fair bit of heads up but didn't enjoy the bum hunting element to it. Thankfully Zoom solves this problem as you can just jump into the action without having to sit and wait for a non reg to sit you.
They also have CAP heads up tables which I also dabbled in. They should probably be called crack tables because they are highly addictive. I don't really know what I'm doing at these CAP games to be honest as I'm not sure about my shove/ fold ranges. But ignorance is bliss and it actually makes it more fun when you don't know what your doing.
I will keep playing the 50nl normal heads up tables for a while and see what my results look like after a meaningful sample.