I have both. My Gucci wallets are all leather, zippy wallets! Love them carried them everyday for a year and they still look and work great! I have a canvas one but haven't had the chance to use it. I also have LV canvas and leather, no complaints here but I haven't had them even a year yet.
Gucci is cheaper but that doesn't mean the quality is as well. I think if your going for a canvas wallet, I'd go with LV all day.....Gucci canvas is softer and tends to look dingy. But if you're looking at leather, either would work great! Gucci leather is sooooo soft yet durable. And while I love LV Epi leather, it just doesn't have the same softness. I've been consumer of Gucci since I was 16, mostly buying their leather bags, wallets, and shoes and I've never had even the slightest issue with any of it!
HTH
PS I wonder if the wallets ppl have said deteriorated were Gucci canvas or leather??? Just curious...