To me a frameless pack is best reserved for daypacks of not more than 20 liters.
The small weight of the two ovaled aluminum tubes in my old REI Cruise UL 60 is a "price" I'm willing to pay for load transfer to my padded waistbelt (yet another small weight price). The comfort and weight off my shoulders and thus my spinal column is a necessity for me.
Adding side panels to a frameless backpack is interesting but the added weight would be better spent on at least a single, contoured, vertical aluminum stay for weight transfer. I prefer two stays for best comfort and pack contour.
The side panels don't transfer weight but merely create some form to the pack. After reading the article I still cannot see much advantage of side panels over, say, side compression straps. Packs without frames and with side panels can still "barrel" down the back.
P.S. I contend (yet once again) that my idea of creating two internal or external fabric tubes sewn to the pack to contain the rolled upper and lower CFC matress halves will give a fairly rigid but forgiving "frame" to a framless pack. Plus it creates a grooove right over the spine for comfort and airflow.