One must always remember that a canopy is basically a sail. Sails are used to move even HUGE ships across oceans. So we should not be surprised that they work well to move small frames.
I've been using the same easy-up since the late 90's. And it cost me about 80 bucks at Sam's Club. It even mostly survived the tornado at LDRS 25 in Amarillo. It did break a couple of the scissor-side-spreading-bar-parts when the tornado hit, but there were literally dozens of canopies in the dumpster and I got some spare parts and replaced the two bars that were broken. The color doesn't match but who cares. And yes it has the splayed legs. I was trying to get the canopy down when the storm hit, but I was too late. Tossed my canopy and about everybody else's in a matter of seconds.
The busted up canopies in the dumpster were aluminum, steel, splayed legs, straight legs, home made, commercial, actually professional quality, you name it. They all had a couple of things in common: they were still up when the seemingly solid wall of wind struck and they all had their sail still in place when the wind hit. Those that had their canopies off when the wind hit were mostly ok, unless a canopy with its "sail" in place grabbed hold and tossed it anyway. Lots of new canopies bought that next day.
The secret for me is the "securely tied down to the ground" part. I tie it down to my van on one end and stake it down on the other. Yes, it is about on its last legs, but mostly because the canopy cover itself is simply wearing out. Somebody at LDRS this last week described where to find me by saying I had the grey canopy between the two white ones. Originally it was dark green but the sun has bleached it to a green/grey color. But it still works and for me, that's that part that counts.
When its time to replace it, I will go with a vertical leg variety and probably get two of them and stake them together. I will use real steel fence posts driven at east two feet into the ground and then tied down with heavy duty straps. Go look at Tim the Wild Man's canopy some time. It doesn't blow away in a storm.
Brad, the "Rocket Rev.," Wilson