"I have a pair of Serratus panniers from the mid 80s (purchased at MEC) that have seen lots of tours and commuting use since then. They've served me very well indeed."

Same here. One of the front paniers was in constant use as my comute or short trip bag, and I can't tell which one it is. At the time seratus was making them, there were two attachment systems. One used the standard hooks and bungies, the other used two straps and D rings, buckles and velcro. That's the one I bought, and while it can be awkward at times, it is bomber solid, stable, and it will never fall off a rack that like the Blackburn (back then about the only one people used) has ears to hang the d rings over. I think the system is not as nicely engineered as the Otlieb, but certainly more secure. Otlieb's mounting system is only middle of the pack.

I remember a time before cordura was popular. Unfortunately people will almost always sellect cordura when given a choice. The much lighter Pack coth is actually waterproof as a fabric, while cordura rarely is after much wear. If the MEC bags were made of packcloth, I think they would be pretty waterproof. In cordura thay are more water resistant. However I just bag my stuff, and then they are truly waterproof.

As others have mentioned the MEC are on the small size. They are big enough to do a trans am if you packed light. They are not freighter packs. I have done 2 week trips, unsuported, and I get by, so it's possible to just keep running them out for longer periods, but you would probably be hard put to carry a lot of other stuff at the same time. Like if you wanted to carry a range of clothing or more than a few days food at a time. In particular I think the front bags are too small if you want to run with a significant weight forward bias.

My ark, I think your pal is correct about the MEC cordura relative to some other designs. It's not as waterproof as the Otlied or a frikin complicated as the Arkel. There is a level where it just keeps getting more and more complex and expensive, say Beckmann stuff. But for simple bags they do a quality job.