In theory, giving students work to do in groups is great. In practice, it can be really tough to do it in a way that's fair. I imagine most people on f.ds were/are generally really great, smart, hardworking students, and we've probably all had the frustrating experiences that come with that. You get stuck in a group with people who just don't or can't work at your level, and "group project" just ends up meaning a mega-project, that you still do by yourself, and to make matters worse, they often still get equal credit for all of your work.
Managing your team is part of it, but there's only so much you can do. I had a project I did last year, where I was the only one making any effort to do anything. I would email, text, facebook message my partners, and get no response. When we agreed upon a date and time to meet and work together on it (which was literally on the day it was due), I was the only one who showed up. No responses when I tried to communicate with them in any way. So I finally just sent an email to the professor the night it was due, saying "here's what I did, I've done everything I can and my partners aren't cooperating".
Anyway, it all ended up working out okay, because the professor was very reasonable, and gave us an extension. I got an A, I don't know if my partners got the same grade or not, part of me hopes they didn't. I think we had one of those things where, you get a certain amount of "points" to distribute among your partners after the project, to say how productive they were. I really like those, that's the best way to do group projects. It makes it so not everyone can just give each other 10/10, you actually have to compare them against each other.
So yeah, I think group work is fine if it's done reasonably. That particular project was stressful for me, but it worked out okay because the professor was reasonable and gave everyone (I hope) the grades they deserved. What I hate is how often that same situation occurs, and everyone in the group gets a grade that reflects the average of the work put in by all members. Like, if I did A-level work and my partners did D-level work, so we all get C's. That's the worst.