Sheri,
Your article neglected to mention a significant downside of diving with PST, Worthington, and Faber (and other) high pressure steel cylinders. A recreational, open water diver should be weighted such that, with a full cylinder and a completely empty BCD, he or she should be able to establish *positive* buoyancy at the surface by simply dropping his or her weight belt. However, when full, these high pressure steel cylinders are so negatively buoyant that a diver just might not be able to do this—especially if he or she is wearing a thin, or no, wetsuit.
And, of course, this has obvious implications for recovering a non-responsive diver from depth, too.
Note: This is less of a concern when using the old steel USD (PST) 72's (71.2 cu ft at 2,250+10%=2,475 psig)—especially when diving in salt water.
Safe Diving,
rx7diver