Sidemount is even MORE fun -- in the water. But you add the nuisance value of two tanks to the complexity of the gearing up, and it may even be less appealing than backmounted doubles, depending on the diving circumstances.
Can't I just dive doubles for a while (smiley face)? I'm really enjoying their compactness and not having an AL 30 pulling at my chest D-ring and being in my face. Right now, I hardly notice the weight and love having nothing but space below me. My propulsion, in all directions, is much more efficient and faster with looong glides between frog kicks (modified FK is my main kick). I feel like a mini attack submarine .......
(without the torpedoes).