I mean, what's all this about, "unless you're going to go up a mountain"?
It's a mountain bike!
Of course you should be taking it up a mountain!
Or at least the closest thing you have to one!
Personally, I don't see much point in not fitting one. Yeah, I only use mine on steep climbs, but it's still nice to have. And as OAH points out, without there is a slightly higher risk of slipping off the middle and into the frame by mistake. Even if the limits on the FD have been set to account for it not being there, the more you ride it, the more risk there's gonna be once cable get stretched out, Etc. I mean, the shifter
reeeeeallly wants to go down there!
It adds next to no weight (the frame is ti!) and it's not like you can even really see it.
Anyway, I suppose there's a million arguments for not using it, either.
As for bottle cages...
I dunno, honestly. Whatever looks good around that lovely old Merlin bottle you scored! Unless you want to send that my way? As I will very GLADLY take it off your hands!
I'm just sticking some American Classic cages on mine for the time being, mostly because I have a surplus of them around the place!
Not sure what I'll go for when I really need to think about it...
I like the old school black plastic Zefal cages I've seen a few people run on their Merlin's. Or the Specialized equivalent. I have a couple of Zefal's too, if the mood takes.