I have Ecopia EP422 Plus tires currrently on with about 36.5 k miles. Just measured tread depth in all groves and minimum in just under 5/32 in one outside groove with most at 5/32 or just above. Cold tire pressure averages 47.2 psi (measured with ForScan App) at about 60 F ambient.
Assuming initial tread depth is 10/32 per spec, I'm get about 7.3 k miles per 1/32 on the Ecopias. I usually replace my tires at just above wear bars or 3/32. So, I'll should get at least 50 k miles out of the Ecopias.
I replaced my OEM Michelins at 48 k miles because of excessive tire noise (rear camber issue - developed saw tooth edges and slight cupping on rear tires) with about 4/32 tread wear. Here's SnowStorm's rear camber fix. Without tire noise, I believe I would have achieved 60 k miles on the Michelins if I could have put up with the noise on cross country trips. So, based on my experience, I'd say the Michelins will last longer.
Currently, there is some feathering that I can feel on the Ecopias and some tire noise that maxs out at about 45 - 55 mph. We'll see if it gets worse. Also, it's hard to tell if there is a significant fuel economy difference between the tires. But, I will say that I don't believe the Ecopias yield higher FE. Based on simple averages of many longer highway trips, I'd say that the Michelins may be better by a several tenths of a mpg at highway speeds.
Bottom line: is the cost saving worth it for the Ecopias? I saved about $100 with the Ecopias over the Michelins (includes $70 rebates for both sets). I'd say gas has averaged around $2+ a gallon since putting on the Ecopias. So, the savings buys at most 50 gallons of fuel or about 2000 miles of driving - probably not worth buying the Ecopias.
Also, as far as handling, it's difficult for me to compare as the Michelins were worn and the Ecopias were new. Best bet is to look at Tire Rack surveys. Neither gets stellar consumer ratings. I'll probably go with another brand when I replace tires again.