Not sure what everyone else's experience is, but I've been on the receiving end of a few ATIs and they've all gotten to me at the point where it's already at/past the reply date. Sometimes it's because it takes a while to figure out who to route it to, which is fair I think, but other times it should be obvious (especially when the organization is named specifically in the request), but still takes 30+ days to get to the people with the info.
Pretty skeptical of the ATI office though; they have released multiple files with things marked up for redaction that never get done, or blatantly secret documents (like the CAF emergency response plan a few years ago).
Overall it's a pretty frustrating process when you get nailed at the last minute (especially with a fishing expedition ATI that goes back to longer than we are required to keep records for) and have to drop everything to comb through a pile of stuff because 98% of the timeline was eaten up by the routing, and generally you don't get BGH support to push back against an unreasonable turnaround time.