I think i know what you mean by gabled, but please confirm.
If by gabled you mean the zips run parallel to the ground, rather than flat meaning they run from where the awning attaches to the van, down at an angle to meet the poles, go with gabled. The actual gable gives you a little extra shade when not using the walls. It is a tiny bit more difficult to roll up, but not a whole lot.
Is this whatt you mean by gabled? the triangular section at each end??