Group work is a very valuable experience to have as most workplaces involve working as part of a team, whether that's in McDonalds or a professional job.
Group work can be a nightmare if there are people in your group who don't do their equal share, don't turn up to meetings etc. I have been in some awful groups during uni, including one where I had to go through everyone's work and correct their spelling/grammar mistakes (no, they weren't internationals!) as it was so BAD.
On the other hand, the last group I was in went smoothly - everyone contributed their ideas and nobody slacked off. It was brilliant and we all got high marks.
I think group work prepares you for life in general - sometimes you have to put up with things you'd rather not and you learn to compromise. Useful, but a nightmare at the same time.