We have been in the market recently for a new rig, and are not brand-loyal.
With that said, we looked at both, and I would go with the Coachmen any day over the Jayco. We looked at new Jayco trailers at Camping World and were shocked at how bad the fit and finish looked on them compared to the competitors at a nearby dealership.
Jayco touts the two-year warranty, but Forest River offers a second-year warranty on its trailers for $150. We got it on our Rockwood. Honestly, I don't know why they don't make it standard.
We have also looked at Open Range (Highland Ridge, a subsidiary of Jayco, but independently managed), who also offers a two-year warranty, and they are far better than the Jayco brand, and on par or slightly better than Coachmen, IMO.