There are no Premium Select (DL's PE product) marketed cabins or fares domestically. However, they do at times run international equipment with PS cabins on domestic routes. When this happens, they sell the PS cabin seats with Comfort+ marketing and fares. JFK-DEN has a 764 in the schedule through October which has a PS cabin. These will be better than regular Comfort+ seats (which are just coach seats with more legroom), however service will still be standard domestic Comfort+. The PS seats are slightly wide than regular coach seats, but not significantly so and you will still have a shared armrest with your neighbor. There'll be better snack selection than coach and free booze, but no meals. You can find information on Premium Select seats on Delta's website -- https://www.delta.com/us/en/onboard/...remium-economy