When LB was little, I never used the BOB. Even six months postpartum, it seemed overwhelming to drag it up the stairs from the basement and then down the stairs to the street. And once it was on the street, I had to quickly grab LB, so no one had a chance to steal the very valuable BOB. I was kind of worried that we had wasted our money on a stroller that would sit in our basement for years until we gave it away (like the drum set).
Then we moved to Providence and started commuting a little over a mile each way to daycare. Now we use the BOB at least five days a week and around 15 miles a week. We've done this through a New England fall and winter, which has included driving rain, snow, and what the meteorologists have been calling a "frigid Arctic blast."
In order to commute through all of these conditions, we have purchased a BOB weather shield and a "personal safety light" for strolling at dusk (I clip the light onto the nose of the weather shield). I've thought about getting or making some wheat bags to put in the stroller for extra warmth, and I see that BOB has it's own brand of fleecy seat cover, but for now we just wrap LB in a blanket, which works fine.
The weather shield works amazingly well in the rain. We've come home during some crazy rainstorm and LB was always dry at the end of the ride. B and I, however, always get soaked. Theoretically it's possible to drive the BOB and hold an umbrella, but in practice it's difficult. I usually just accept that I'm going to get wet and try to walk as fast as possible. B and I should probably invest in full length slickers.
The BOB has really good traction on ice, and I usually feel safer walking with the BOB on ice than I do without it.
The BOB does fine on packed snow and cleared walks, but it loses traction if I try and push it through even a few inches of unpacked snow. At corners where snow has been piled up by plows, I often had to pick the stroller up and carry it over the snowbank. That part sucks, but a few people have been nice enough to help a sweaty, middle-aged woman hump a stroller over a snowbank.
LB seems to stay nice and cozy inside her bubble even in high winds, and the BOB is heavy enough that it stays stable in wind.