I'll spoil it for you, they get f***ed up. I'm not looking for sympathy, but I think my experience goes against some 'expert' wisdom on using these hubs in winter.
So I decided to build my first real track bike this fall. I've been working as a messenger for about two years, and have been using conversions and decent 80s' road bikes, for most of that time. Given that my road bike got smashed up last spring I decided to stay on the fixed all summer, or at least until I made enough to rebuild the thing. Anyway I ended up fixing the roadie only to get hit again the first week I was back on it. At this point I decided to permanently make my main work bike a fixed, more specifically a track bike.
Long story short, I set a budget that included a set of D/A-Open pro wheels off of Ebay. I'm part time right now, so I baseline at 3 days a week and usually work more, but never less. So at 50 or so miles a day these hubs saw 3 weeks, or just shy of 500 miles of riding including non-work riding. After this point I retired the trackie and got on my winter conversion. Of the days I rode the D/As one rained hard, and one was kind of slushy, the rest were clear and dry. I removed the wheels every couple of days to check the bearings, and eventually found that both the front and rear hubs had gotten a little rough.
I repacked the front just before putting the bike away, there was no pitting or rust. I just opened up the rear and, well, check the pictures.
Only the non-drive side or the rear had this damage, but it wasn't limited to the cones, the races are pitted too. I'll see in a minute how this effects the smoothness of the hub. I know about maintaining loose-hubs having run shimano stuff on all types of bikes since before I was a messenger, I've just never seen one go to hell so quickly.
These are great hubs, laced to open pros, these are the fastest and most responsive wheels I've ever owned. Paired with a decent drivetrain and frame I found the performance increase over Formulas more than noticeable, it was extreme. That said I wouldn't recommend anyone use them in the winter, even with the seals installed. Keep e'm dry, the bi-weekly maintenance is really a pain otherwise.