I think it all depends on the group. I've been to lots of different ones (over 8 years and 4 towns!), and have found them very hit and miss.
For me, I enjoy sitting in weigh in thinking to myself 'I've lost more than you' - I know it's small, and silly, but it's that which keeps me going. Strange as I'm never competitive in anything else!!
Of all the different groups i've been two, i've only found 2 which were worth staying. The first good group was my first group - the consultant knew the plan inside out, always kept the meeting to the point, whilst also being sociable and very very informative, and even the 'lifers' in the group who weren't really there to lose weight, still got involved in the meeting.
The second was the group I've just re-joined, and the original consultant was brilliant - she had good and bad days like everyone else on the plan, and she was happy to share her ups and downs. She was also very supportive of everyone individually, so everyone felt like they had her attention when they needed it. It's a different consultant now, and she's not as good (well that my opinion anyway), but the dynamic within the group seems to have remained. So I'm going to stick it out.
I've found at a lot of the groups though, people aren't really there to lose weight, the consultants often don't know the plan 100%, or can be patronising and not keen to have members share information between themselves. I also think a lot of people are very uninspired to clap 40 times over, or last year when they had that stupid 'game' in class where two sides of the room were supposed to be competing for points each week - Just a waste of time, made the meeting longer and seemed completely pointless!
Anyway, I guess my point is that there's a lot of groups out there that sadly don't offer the support and inspiration that they should, but there are also those that do!