Recovery was roughly 90 seconds on those reps. Managed to be consistent through the session, within 3 or 4 seconds for each rep. Within the rep it was maybe a shade faster for the first 400, slight fade towards end of rep but not a complete meltdown.
I've scaled back recently. I was marathon training for most of the year for Yorkshire marathon, but picked up a mortons neuroma which finished me off in September. I've dropped back now to a base of 3 runs a week (with the occasional parkrun taking me to 4). Typical schedule is Tuesday speed work, Thursday tempo run, Sunday long steady run. When doing reps, I try and get them under 6mm, the tempo runs are a shade under 7mm, and the long runs just under the 8mm (as a broad rule). Last few weeks looks something like: