Hello, my first post, so let me start with the obligatory "Wow, this is the real modern X-com, awesome, thank you!"
Now that is out of the way, I think the troops could use an additional equipment slot in addition to armor, weapons and stuff they are carrying. I'm talking gadgets - things like visors and such. You could have a simple selection available and other things you need to research and produce. You could tie the gadget slots to the type of armor, thus increasing tactical considerations. For example, the heavier the armor, the less slots it has, while going naked gives you three or even four gadget slots. Here are some ideas on what the additional gadgets could be, just as examples of course.
EarthTech gadgets:
Night-Vision Goggles (Self-evident)
Gasmask (Self-evident)
Armor plates (More armor, heavy!)
Lucky charm (+Bravery)
Stuff you need to research:
Ablative vest (More armor, heavy!)
Combat HUD (+Reaction/Accuracy)
Targeting matrix (+Accuracy)
Autodoc (Stops bleeding on its own)
PSI Shield (Protects from PSI)
Alien scrambler (Aliens less likely to target)
Alien beacon (Aliens more likely to target)
Anti-grav harness (Faster movement)
Supreme Night-Vision (Self-evident)
Hydraulic sling (Throws grenades much further)
Exoskeleton (+Strength)
Helping hand (Additional hand slot)
Sensor matrix (Wider field of vision)