[Michael Chandra]

(plus the normal recovery time for installing the new augmentation)

Which in Missions is covered by a simple generic 1-week recovery period.

[Csjarrat]

I don't see what the problem is for upgrading glasses/earbuds etc, this just falls under build/repair skills using hardware skill.
-Source components
-Source plans
-Grab tools
-Do work.

No different for guns/armour mods, just use armourer skill.

Upgrading cyber eyes/arms is same, done with biotech skill.
Many augs need to be ripped out and replaced however.

[Michael Chandra]

You could houserule it to use that, yes, but Armor and Audio/Vision Enhancements had no upgrading rules in SR4. Only rules on what you could stuff in them, and rules for Guns + Vehicles. SR5 has no rules on it either.

[Csjarrat]

Page 128 of arsenal (sr4) says otherwise mate:
Modification rules are designed for weapons/vehicles but can be applied to any sort of gear modifications if the gamemaster so desires

[Michael Chandra]

In other words, GM's call.

[Csjarrat]

In other words, GM's call.

Theres the rules as presented for you, if you dont wanna use them. don't.
The thread is about what does a character do to mod gear after chargen, well he does exactly what it says in arsenal. simples.

[Michael Chandra]

You're right, there's a rule for SR4 where the GM decides. So maybe Run&Gun will have one for SR5.

By the way, GM's call is never just plain simple, since it's not a matter of whether you want to use them, it's a matter of whether the GM allows you to use them.