ok, this is something I did to really just convince myself that proportion is important erh, so this might not be very useful for everyone, but stil, i figured, why not..
it's 9 pics of daVinci's "man". the up-left man has both correct form and proportion. downwards means worse proportion, and rightwards means worse form.. well.. see for yourself and decide if proportion is important.. hehe..
seriously, i think this shows that even though the form might look like s**t - good proportion stil shows "through"! and this in turn means that all those sketchy drawings that i did way back then that look "wrong" is more about proportion than form.. erh.. again, not very interesting for you maybe..