Your cooldown was a pace I'd be happy to run at, let alone the fast bits!
Funnily enough that's not my fastest km of this recent blob of training, nor my fastest 3km. But it's the best I've felt lately and that's encouraging. A bit sore in my original leg injury (L gastroc) but resting and then pushing later. I'll take this glimmer of hope and, er, run with it.