I agree - sod the time, go for distance every time.
I see them at every race keen young lads (usually in MUFC football kit) who push to the front and blast off like whippets only to be passed after two miles, by several fat smiling old men with bad knees .
The object of distance running is endurance, increased pace usually comes with increased mileage. It's like charging up a battery long slow miles in = shorter faster miles out.
Aim to eventually complete 10k(6.2M) in something like an hour without stopping.