I'm ready to buy my first trainer, and have narrowed choices down to a Goldberg Eagle or Sig Kadet LT-40. During my research, I have noticedthat some recommend outfitting the plane with a midsize engine while others recommend opting for the largest engine available for your particular plane. The Eagle (if I remember correctly) recommends a .29 to .45 2 stroke. I have been considering either a .40 or .46 size. Any pros and cons either way? Is this small difference in displacement going to make much of a difference in the air? I've been looking mainly at OS engines but am open to suggestions. Thanks.