The biggest difference, other than unique factors that we don't know about your building is cost.
The gable end really doesn't do much in a modern building, so you don't need a beefy header across your doorway.
On the (I'm assuming here) long dimension, you have trusses sitting on the walls. Those trusses need support, so you'll need to add vertical supports and headers to carry the load. If your "entry doors" are 3' wide, you'll need to span 2 studs with a moderate sized header. If it's a 20' roll up, you'll need a header that can span 20' and hold all the trusses. This gets more expensive than on the gable end.
For my shop, I'm putting one roll up on the side, and two on the gable end.