I like the idea of being able to work in groups to tech up, but I also like the idea of building up on my own and not getting trashed by a gang of bullies. I also don't like being seriously ahead of someone in tech and having it stolen from me. But stealing tech does add a nice dimension to things.
Maybe limit tech stealing to only those techs that are slightly ahead of what you have. That way people can't leap forward super quick. Also, maybe limit the tech sharing, so instead of just giving it to other people, they'd have to "analyse and digest" the material. So it might take say, half the time to research it?
Working in groups should be beneficial, but only fractionally so. That's especially important if teams are formed of unequal size.