Just a bit of perspective...
While many folks love the Brooks and find it works well for them and on the forums it sounds like the Brooks is almost universally used... Not everyone is in love with Brooks saddles and on the TA this Summer we did not find all that many riders using them. They were definitely in the minority.

I am not saying that the Brooks is bad, but it is after all just a saddle with advantages and disadvantages. Personally I would put a few hundred miles on whatever came on the bike and see how you like it unless it is some wide heavily padded thing. They if it seems fine stick with it.

Personally I found the one Brooks that I owned to be just OK when new and didn't like it after it was broken in. If you are weight conscious they are pretty heavy.

OTOH: The cost of a Brooks isn't all that unreasonable so if you want to see what all of the hype is about, try one.