(At a past startup, we used 80/20 for the structure of our factory stations. We were very happy with how 80/20 was easily adapted during prototyping and testing, and then our final station design could be replicated quickly stateside to several stations, then disassembled into a few assemblies for flight, reassembled at the factory in Asia, and hold up well in production, and it also looked professional for demos. A lot of that success was due to the know-how and effort of our mechE, but, IMHO, 80/20 is appealing to people who grew up with Lego-like toys, and even I, primarily a software person, felt I could do useful things with it and some basic tools.)
My armchair assessment is that both will have their uses. 80/20 is 3-4x the price, but is lighter and more rigid than EMT conduit. EMT conduit is sold everywhere and will be more useful for quick and dirty setups.
For a machine like a 3d printer, I would choose 80/20. For some lightweight shelves, EMT conduit or wood. So I see this product almost as a wood replacement rather than a 80/20 replacement.
Steal can be bent without failing. I believe 80/20 has less flex than a similar sized pipe? But when it gets bent you’re done. So there will be situations where steel is a better choice.
(At a past startup, we used 80/20 for the structure of our factory stations. We were very happy with how 80/20 was easily adapted during prototyping and testing, and then our final station design could be replicated quickly stateside to several stations, then disassembled into a few assemblies for flight, reassembled at the factory in Asia, and hold up well in production, and it also looked professional for demos. A lot of that success was due to the know-how and effort of our mechE, but, IMHO, 80/20 is appealing to people who grew up with Lego-like toys, and even I, primarily a software person, felt I could do useful things with it and some basic tools.)