I know many who don’t like the “bushy” look of the World Tour wigs, so you’re not alone there. :) As for Meg being brunette or blonde, i don’t have any strong preferences, but I like that there is a colour contrast between Christine and Meg.
I don’t think Broadway has ever had brunette Megs. That is, some of the Megs wears a very dark blonde wig, which can look surprisingly dark in photos. But they aren’t exactly brown. More like a dirty blonde shade:
I don’t think Japan has had brunette Megs either? They go with medium blonde wigs there, at least those I’ve seen photos of:
But there has been several brunette Megs elsewhere. All the South Korean Megs (in the Korean languaged version) were brunettes, wearing very dark wigs. The same was the case with Jee Hyun Noh, who’s been principal Meg in the World Tour. She still understudies the role, and she still wears a dark wig. Here she is to the left:
The original Australian production and tour also featured dark haired megs, in particular Sharon Millerchip (who started with a blonde wig, but got a medium brown one later in her run) and Christina Tan (who wore a dark wig).
Other brunette Megs includes Lucy Potter (left, Hamburg/West End) and Julie Collins (right, Hamburg):
Also, see: http://operafantomet.tumblr.com/post/65253129304/dark-haired-meg-girys-as-requested-by
Paloma Garcia Lee was a darker more strawberry blonde too, you can see it here:
Of course, there’s a palpable difference off-stage and on-stage.