When me and keith decided to change performance fords binding away from perfect bound it was purely a style choice - the thinking was to incorporate the extra staples for the tech section in the middle, which enabled you to pull that section out and keep it. A la fast car mag in the '90s. Also, I think perfect bound works better on really fat mags, a nice by-product of switching to saddle stitched was it made our mag look and feel more full!
Shame to hear things are that dire that mags are having to switch bindings to reduce costs!
Ben