Playing Favourites

So I've written a lot during the past month, and I'm whipping through September's chapter of Children of the Apocalypse (the characters, they beckon...I've reached the point where I reward getting mundane work done by then letting myself write 1K words of CotA).

I'm looking at the characters and subjects that are dominating this part of the story and it's raised some concerns I have...

You know what it's like when you're watching a show or reading a series of books, and there's that character that's kinda fun, but the writer clearly loves them WAY too much and soon it becomes the ____ show rather than an ensemble? For me, that's John Locke on Lost, or Spike during the latter part of Buffy (look, I love Spike, and I know James Marsters has amazing screen presence, but a lot of the time it felt like Spike's wacky adventures, and not about the Scoobs)...so now I'm a little worried that I'm going to overdo it with a character that's my personal favourite.

How objective can a writer be about her favourites?

Also, is there such a thing as TOO much Michael in Children of the Apocalypse? Go vote in this poll and let me know. I really am curious...