Had the GE Monogram in my former house when we re-did kitchen 3 years ago. Disliked them. Long pre-heat times; loud; fan throws out tons of heat (although most do it was a noticeable difference) and took forever to cool down so the fan was running for a long time after cooking was complete; and even though I checked temp it was uneven baking. Don't know about the Jenn-Air. I put Dacor in the new house and unfortunately have had nothing but trouble. Contractor working with appliance sales now to get them out of here!