Edit floods are based really on the traffic of your site, and how much of an impact it will cause. For example, on Stack Overflow, you could probably do a flood of 150 edits in the span of an hour, and it'll have almost no impact - the front page moves fast enough to override even that much, and the special "Interesting" view may even completely overlook these revisions. However, on many of the small Stack Exchange 2.0 sites, they don't get enough traffic to overwhelm a full front-page worth of edits (which is 50, by the way). As such, judge the appropriate frequency based on your site performance. Aaronut wrote an interesting analysis of Seasoned Advice's traffic with regards to 'edit floods', consider using that as an example of what to look at.

Super User is one of the higher performing sites so you're probably more in Stack Overflow's shoes than in a small site's. However, you also want to keep in mind, the faster a massive edit session is done, the less impact it will have on your traffic. It may overwhelm the front page for an hour, but after that hour, it could be recovered by your normal traffic very easily, with the added bonus that the edit job will be done.

You may consider that it is often wiser to perform massive edit jobs during low period hours. That way, any impact you do have on the front page, will be during a period of time when there isn't much for the revisions to take away from. As well, when the activity of the site does pick up, it'll again clear up all of the leftovers from the edit flood.

I'd say that ultimately, the biggest thing to keep in mind about an edit flood is prepare in advance for it. These should be planned efforts to maximize the amount affected while minimizing the impact on the site. Determine whether it is a tiny job of 20-30 posts that can just be done any time in the day at any rate, versus a job of 100+ that is best done overnight in one fell swoop.

To take away from it, as long as it is improving the site and not significantly detracting from your normal site activity, I'd say that such things should not be discouraged. We needn't necessarily encourage them, but I think they're fine when they work without harm. There's little that can be done post-fact other than discuss how to do it better (if there were any issues).

Edit floods are based really on the traffic of your site, and how much of an impact it will cause. For example, on Stack Overflow, you could probably do a flood of 150 edits in the span of an hour, and it'll have almost no impact - the front page moves fast enough to override even that much, and the special "Interesting" view may even completely overlook these revisions. However, on many of the small Stack Exchange 2.0 sites, they don't get enough traffic to overwhelm a full front-page worth of edits (which is 50, by the way). As such, judge the appropriate frequency based on your site performance. Aaronut wrote an interesting analysis of Seasoned Advice's traffic with regards to 'edit floods', consider using that as an example of what to look at.

Super User is one of the higher performing sites so you're probably more in Stack Overflow's shoes than in a small site's. However, you also want to keep in mind, the faster a massive edit session is done, the less impact it will have on your traffic. It may overwhelm the front page for an hour, but after that hour, it could be recovered by your normal traffic very easily, with the added bonus that the edit job will be done.

You may consider that it is often wiser to perform massive edit jobs during low period hours. That way, any impact you do have on the front page, will be during a period of time when there isn't much for the revisions to take away from. As well, when the activity of the site does pick up, it'll again clear up all of the leftovers from the edit flood.

I'd say that ultimately, the biggest thing to keep in mind about an edit flood is prepare in advance for it. These should be planned efforts to maximize the amount affected while minimizing the impact on the site. Determine whether it is a tiny job of 20-30 posts that can just be done any time in the day at any rate, versus a job of 100+ that is best done overnight in one fell swoop.

To take away from it, as long as it is improving the site and not significantly detracting from your normal site activity, I'd say that such things should not be discouraged. We needn't necessarily encourage them, but I think they're fine when they work without harm. There's little that can be done post-fact other than discuss how to do it better (if there were any issues).