I generally sit quarter-lotus. In doing this, I find there are two ways to hold the mudra.

1. With thumbs at height of navel, blades of hands against lower abdomen, resting on nothing, elbows a bit further away from the body.
2. With wrists resting on inner thighs, mudra down in front of the groin area, elbows a bit closer to the body.

In terms of physical mechanics, is there a difference/benefit between these two methods or is it a matter of comfort for the practitioner?