id probably prefer to work on a nice set of headfones rather than one speaker i think! or maybe you could switch from both hfones and the mono out. i suppose its how you look at it tho... i just dont know if i see the point in making tracks for mono systems.. when there is so much more technology available...
either way if u spend the time working on mono... or just spent it making loops, paches etc... youre going to have to go back and rework them someway when u get sorted.