I have children in both GS and Cubs. I prefer the Cubscouts, but as yet in my area they do not allow girls in.
I find running the GS troop makes a huge difference, we require more for our children - though age based. Meaning the daisy group doesn't have very strict requirements to earn a fun badge for going to the observatory. The jr level however does have a stricter list.
If you decide to join, know the troop leader in question is far more important than the various national level policies. The new changes they are making (but not sharing with us) will effect things as well.
If you join one troop looking for camping, or crafts, or speaking/survival skills - you may find what you want right off the bat. Or you may go through several troops - or need to start your own.
I find that the alternatives are not that great of a fit. 4H only goes camping if I choose to lead a camping thing (my kids are in 4H for things like robotics, and public speaking though). the various new super Christian groups tend to be so far on the 'girls are homemakers' side they they turn me off. the Y has a group thing, but it is so expensive. YMMV
Instead I bring my whole family on all cub events that I can and we try our best to make our GS troop as much like a Cub pack as we can. If cub Scouting ever goes co-ed we will be switching to a whole family of cubs!