The larger wheel will make it easier to steer and maintain direction due to the extra leverage .It will also slow your steering "response" due to having to make larger movement with your arms to get to same degree of turn and you will need to turn *the wheel more quickly.Just depends on how you want it to feel.You know----personal preference.I would not like it myself with a 12" wheel. If the steering feels too heavy you may need to investigate your geometry.Especially the scrub radius and castor. Just my 2 cents worth of advise worth absolutely nothing.
