Here's how they came out:
The right handed one probably is a better likeness, but I actually prefer the style of the left handed portrait. I seem to be less hard with the pencil so it's a lot looser and somehow I look more relaxed!
This is a fun exercise to do. It only take 5 minutes and all you need is a pencil, a piece of paper and a mirror. Or if photography is more your thing, have a go at taking your own picture, using a tripod and the timer function. You'll learn a lot!