The window was *far* smaller. However, the question is not did anyone ever suffer any data loss. It's how many people and how much data in comparison to other filesystems. I know of no other filesystem as resilient at its default settings as was the pre2.6.31 (or so) ext3. I also never noticed any performance problems. Certainly nothing that my customers cared about.
And of course, we can still mount ext3 explicitly data=ordered.
Oh for the days when Linux filesystem devs cared more about reliability than benchmarks... no matter whose fault the data loss might be. Things have changed since the Tweedie days.
Today, I use ext4 with nodelalloc. I tried ext4 at its defaults. But the first time power was lost (and the UPS failed) we had to rebuild a bunch of C/ISAM files. Never in our long history with ext3 did we *ever* have anything like that happen. (And my customers are bad about letting their UPS's go.) Personally, I think nodelalloc should be default, with delalloc available as a mount option.
Current Linux filesystem devs just seem reckless to me.