Adding 4 circuits, options?

I do mainly commercial work, so when helping a fellow electrician doing some residential work we ran into this "difference" of style how to add 4 circuits.

Basic single level house, they wanted to add a 4 circuits to the pantry/garage they were having remodeled. Panel has space, also has an open 60amp breaker. Main panel is about 60-70' away surface mount on an outside wall. Pretty open attic access, basically a straight shot.

He wanted to go romex with 4 home runs route, adding 4 20s.

I wanted to go THHN to a sub panel reusing that breaker or swapping to something appropriate.

We figured the price would be about the same. Maybe a bit more in labor doing the sub panel, but we aren't talking more then an hour. We figured only real advantage either way so future expandability if you add the load center.

Which would you do and why? This wasn't a "what do we have with us" job, so just because you have it doesn't make it the right answer.