I certainly don't want to discourage your purchase...I know what its like to buy a new rig! However, I also think there are some wise thoughts in what Scott says.
We bought our first RV used. Learned a lot about RVing and what we wanted in an RV. Had that rig for only three years before we moved up to a new rig. Sold it for almost what we purchased it for.
To answer your question...get the one DW likes best! I have had a Keystone product but not a Jayco. If I was in the market again for something like you are considering, I think I would try a Jayco.
