The item description for medium chimeric armor says it "is as strong as plasteel but much lighter".
But both weigh 3 tons.

assumedpseudonym 17 Mar 2021:

 Stuff like this is exactly why I’m against the standardization of armor mass classes.

kourtious 17 Mar 2021:

Adding to that. Standardization of armor mass classes is fine for newer players but after a few games, the concept of your armor being too heavy or causing slow downs is already given in the tool tip. Therefore it is not a hard concept to grasp.

george moromisato 12 days ago:

Added regen to chimeric armor to differentiate.