yea but if your going for HP complex is the way to go, you know like heavies.. thou most never see it that way.

mobility isn't why I kill heavies. mobility might help the assault class/logi but a class that already has low mobility it isn't that big of a hit.

Two Basic Plates

15 more armor hp
Less movement penalty (6 percent as opposed to 10)
Less CPU cost (10 less)
Less PG cost (10 less)
2,145 ISK cheaper

Just saying, if you have the slots, might as well use them.

In fact, overall, it's better to any combination of two basic/enhanced plates than to use one complex. Two enhanced will give you almost 60 more HP over one complex with the same movement speed penalty and PG cost at the expense of needing 10 more CPU and being a little more expensive.

Indeed.
I have talked about this issue, and other armour issues, at length.

It's been discussed before. It's a broken system and I advise my newbros to be absolutely sure that they need the higher tier plates before speccing any higher than 1. It's just not worth it to go any higher for a everyone but a heavy that is going for a pure armor buffer fit. nobody else needs to take that skill any higher, and that should concern CCP as they likely don;t want there to be skills commonly viewed as useless

It's been discussed before. It's a broken system and I advise my newbros to be absolutely sure that they need the higher tier plates before speccing any higher than 1. It's just not worth it to go any higher for a everyone but a heavy that is going for a pure armor buffer fit. nobody else needs to take that skill any higher, and that should concern CCP as they likely don;t want there to be skills commonly viewed as useless

Two Basic Plates

15 more armor hp
Less movement penalty (6 percent as opposed to 10)
Less CPU cost (10 less)
Less PG cost (10 less)
2,145 ISK cheaper

Just saying, if you have the slots, might as well use them.

In fact, overall, it's better to any combination of two basic/enhanced plates than to use one complex. Two enhanced will give you almost 60 more HP over one complex with the same movement speed penalty and PG cost at the expense of needing 10 more CPU and being a little more expensive.

It's a massive hit. Movement speed isn't just running, it's starting and turning as well. Mobility on a heavy doesn't matter as much because they have more shields/armor but to a logo it's crucial

Thus why speed penalty from plates shouldnt hurt base movement stat at all. Only sprint, stamina and jumps height.
No penalty should hurt an attribute that you can restore back through a module. (like sprint with biotics).

Any thoughts toward modules that decrease mass like Nanofibres for Infantry?

Considering we don't have structure, wouldn't the nanofibre just decrease armor amount?

Not really, the movement speed penalty will reduce your survivability through mobility. This is why Shield Tanking, to this day, is the better option.