I just submitted another paper to a journal. While it's not a "top tier" journal, it's one of the best of the remaining ones. And a couple more publications at this level would be sufficient to lock in tenure at my current school. We figured there were several more things we could add to the paper, but there's a competing paper out there which is similar to ours. So in this case it's better to be quick and done than perfect.
It's always a good day when you send a paper off. At that point, it's off your desk and out of your hands (at least until you get the referee report back in a few months).
We figure that if the reviewer likes the idea and wants changes made or additional work done, he or she will tell us. If not, we just saved some work. And time is of the essence here.
So now I have two pieces under review. I still fall short of Mungo's Rule (i.e. have at least three papers under review at all times), but now I'm within shouting distance. And I have another that I think I can finish within the next two weeks (the week after this is Spring Break at my school, so I can work without distraction).