It's really your personal choice. I wouldn't do either at 38weeks but that's just me. The ballon method was beyond my comfort zone ( when that was put forward to me as an option due to my huge baby) and I would do everything possible to avoid a c/section. No one can really tell you what is right for you everyone is different. And my HUGE baby which was estimated to be over 4kg ended up being 3.8kg at 13 days over due.