I guess the advantage of working on multiple paintings at one time is that you get the satisfaction of finishing two in one day!
Its interesting how much of a different process that the canvas painting is to digital. Its a lot slower and you have to wait for stages to dry before you can approach the next, there's no undo function, no editable layers and you can't just pick up objects and reposition them on the canvas. Makes me realise how spoilt we are in this digital age.
On the flip side, you can paint in the sunshine and not be huddled over a computer monitor :)