I prefer no elastic. I have a short torso, hour glass figure and a little less tone on my core than I want right now. BUT I had issues with elastic creeping up when I was 25 lbs lighter. I do find non-elastic jerseys can shift to one side more but they don't ride up over my little "pooch" area so I take non-elastic. I also prefer bib shorts, that is how I roll.
Amanda
2011 Specialized Epic Comp 29er | Specialized Phenom | "Marie Laveau"
2007 Cannondale Synapse Carbon Road | Selle Italia Lady Gel Flow | "Miranda"
You don't have to be great to get started, but you do have to get started to be great. -Lee J. Colan