I have a 2005 Citi and a 2007 Metro. I just looked and the only difference is that the Metro has a plastic impact rim glued to the bottom of the styrofoam, and snaps on the top to attach the rain cover and whatever other accessories, and the rear blinkie strap. Both have the same adjustment system, or pretty close (probably just different due to the years). I don't think the winter kit will fit the Citi either.

That doesn't matter much to me, since the mirror isn't that good, the elastic rain cover I have is fine, and just the rain cover and a balaclava has been more insulation than I've needed down to -25*F so I don't need the winter kit either. Heck, for a couple of years I just duct taped up the vents in the winter and that was fine.

The metro is available in different size ranges. The Citi is only one size, and barely fits me opened up all the way. So for me the Metro Large is a better choice but for the majority of heads, if you weren't going to go for the accessories, the Citi is as good. I got the Metro mainly because at end of year they put them on good sales and I got mine for $35.