I use them in my
IG army. I run 3 with heavy bolters.
I love what you get for such a small amount of points. I decided a while back to fill the last of my roster with those beautiful forgeworld models and I've never looked back.They suit my theme perfectly to boot.
I think the reasons why it seems like they're not used are -
1. They take up a Heavy Support slot. (Which most
IG armies fill up with Arty or Tanks)
2. Whilst they are cheap, they aren't exactly reliable and don't do THAT much
I use them personally to babysit my Fortress and my Arty. With the 360 degree fire to help dissuade deepstrikers etc.
Tbh though, they'd be best in Cities of death where you can set up firing lanes and have them block whole streets.
Ofc, an intelligent opponent can negate most of their bonuses (sending a distraction unit closer to them to eat their automated fire) or outrange/ approach from blind sides depending on the firing mode.
I wouldn't recommend going Camo Nets or Lascannons though. You'd be investing too many points in an unreliable (albeit fun and fluffy) unit. Go Heavy Bolters and any distraction/ kills at all is a bonus for only 45 points.