DD is going into her second year of Daisy's. We love it. They meet every other week for an hour. The first year parents were expected to stay but this year they are not. We are expected to sign up for different responsibilities to help out though. We joined late last year and barely missed cookie sales so I have no experience with that. They learn the Girl Scout Law, read little stories, do crafts, play games or do service projects around the theme of each badge.
We do it. I worked at our local council from 1999--2002 or so. DD1 was a Daisy Girl Scout for 2 years and is going into her 2nd year as a Brownie Girl Scout.
Your experience with Girl Scouts is highly dependent on your local council, and especially upon who your troop leaders are and what they choose to do. There is a lot of freedom/leeway giving to leaders to set up whatever works for them. I like Girl Scouts b/c it fosters friendships, is a character-building type activity (kindness, respect, caring for self & others), and it can allow girls to try new or different things in a safe environment.
At our school, DD has had Girl Scouts once/month, at school, right after school. Parents don't have to stay, but a couple volunteer as helpers for each meeting. Additionally, there are several optional activities throughout the year. I.e. she has done a fall council-wide barn dance (DJ, bounce house, costumes, snacks), rock climbing, a swimming-and-pizza troop party, bridging party, a father-daughter dance, gone to a "princess party" designed by a troop of older girls in the area. There are also things like lock-ins at the Y and sleepovers at the museum but we haven't done those yet. There are tons of camp and educational program activities available through the council. She has done the local day camp for 5 days the past couple summers and really enjoyed it. Our council works to keep things very reasonable. Girl Scouts as an organization tries to be very inclusive.
At their regular meetings, they usually work on one of the badges by doing activities around a certain theme and reading short stories in their Girl Scout books.
As far as cookie sales go, you can do as much as you want with that. We don't do great with individual sales but our troops has several booth sales at local grocery stores, and all girls who participate get a share in the total sold. I think that's actually a great activity for the girls--it's fun, and they have to be friendly, ask people if they want to buy, talk about the varieties and prices, and make change.
We are JUST starting with Boy Scouts (DS is in 1st and will have his first year of Cub Scouts) but from what I have heard anecdotally and seen so far, Boy Scouts seems more structured, more intense, more expensive, and more time-intensive. They have both a small group meeting and a large group meeting each month, from what I can tell. The registration fee is a lot more than GS and so are uniforms.
PS so as far as costs go, with have typically only paid the registration fee, which I think just went from $15 to $20 for the year, and every 2 years you buy a uniform piece and handbook and some basic pins & badges...I think that was maybe only about another $15-$20. We have only been asked to buy a vest for the uniform--not a full uniform with different pieces. Blue vest for Daisies, Brown for Brownies. It's been very reasonable. Some other activities have small fees but most things have been covered by cookie sale money.
They also do some service-project type things. Forgot to note that.