Swings and roundabouts
You have to be careful when discussing browser fix times.
Microsoft may fix a problem in 1 hour flat. However they may not publish it for a month, unless extremely urgent.
Unlike much Open Source (note: much, not all), MS have a single point of contact and they deal with VERY arge businesses.
If they release a fix that then turns out to cripple every system going, they can be held liable. i.e sued. It's difficult to sue a bunch of looselt collected people.
Also MS actually did the month patch fixing in response to alrge number of Admins asking for this. This means they can take the patches. Pilot them and then roll them out. If they have to do this 1 - 5 times a week (remeber we are talking about apps, DB's as well as browsers), Admins get completely bogged down.
So the quick turn around by the OS community is great , but bear in mind, it can also be a burden.