I am dealing with Year one right now, and yes, for the most part they have good service, plus they have 20 to 30 percent discounts when you order online with special sales codes when they are available.
Overall, their interior lower door panels could be better, but there is only one place that makes them(Accu-Form), so whether its Year One or Legendary, you get parts from the same manufacturer. Seat covers and insullation seems pretty good from REM or PUI. Legendary is better at matching seams and having stronger seams, but you will pay a higher price. Legendary does restore upper door panels, which is nice. I got a dash pad from Year One, its not very good, fiberglass core with stretched vinyl over foam, so its not as sharp as the original, so i am going to pay a premium and have Just-Dashes restore my original.
Sheet metal from AMD i find to be good and fit is also good.
Yearone gasket and seal kits i.e., paint kits and firewall kits are not complete, so I found Detroit Muscle Technologies that make complete kits for firewall, heater box restore, and paint kits and you can buy as a kit or individually. Pretty good place for a husband and wife team, if you cant find it, you can send it to them and they make most stuff. They also do a good job with firewall and kicker section insulation and shoddy pads for under your dash.
Year One is good on their wiring harnesses, they seem to be spot on, but that is because there is only one company that makes these and they are licensed by YearOne because Year One owns the rights from Chrysler on the harnesses.
Hope this information helps someone!