Thanks fellas, for the words and info.
I used to long for the XV, which is why I owned four Speedbirds. But my tastes have altered slightly as has my eyesight, and the XVI just seemed a better bet. I also looked at the XVIII but the '9' seemed a bit unnecessary to me, kind of imbalanced the dial to my eyes, and the font seemed a little too rounded; but if there were no XVIs around then I may well have plumped for one over the XV as I still think it's easier to read at a glance (to my older eyes anyway).
I am loving this XVI though. I know they're very simple pieces for the inordinate cash they fetch, but now I have one on my wrist I 'get it'. Strange hobby this!
I'm still loving my Fortis Cosmonaut Chrono however. Both that and this are eternal keepers.