The VI team had been thinking about vortex torpedoes. I like the virus idea and the shield transfer.
Generally, the VI mod has Admech shoot much faster (and had them and SM get better accuracy a long time ago) with a slight dps increase. This makes them better at attacking fast moving targets.
For my own mod version, they now have good boarding, somewhat better side armour and slightly boosted stats and are a bit more expensive than default. I also boosted their range a bit, especially for lances. Their fighters/bombers are also somewhat tougher than regular IN counterparts to make up for the missing assault boats. The ark also has a previously unused Heavy Plasma battery.
Now they can, for example, close and outboard Taus, which both have poor boarding.