I'd go for older/lower mileage any day, rather than newer/higher mileage.
We've had both kinds.
The two we've had that were higher mileage (not stupidly high just average or slightly above average, I think one was around 10k on a car less than a year old, and the other was around 20k for 18 months old), had lots of problems over the time we owned them, so were probably badly driven (gearbox, suspension, etc).
The ones we'd bought new or used with very low mileage have had no problems at all other than routine servicing, consumables, etc. even though we generally keep them many years.
The lower the mileage, the less chance they've been driven by boy racers, travelling reps, engineers, or even hire cars, so less chance they've been driven badly.