I don't know about the new ones, but the Express I bought in 1993 had a pad that was worthless. It looked okay, but what appeared to be a thick pad was really a thin piece of hard rubber stretched over a 'hollow plastic box' that was part and parcel of the spacer. Cheap junk.
Four or five years ago, IIRC, I bought one of the pre-fit Decels that were advertised to fit the current production Express models and had to sand down the edges of the pad to fit. Following the directions, I wrapped the butt in tape and started sanding with some 80-grit on a block of wood. Messy, but it worked and it looks just fine. The edges are smooth and I got the angles correct
Pachmayr Decelerator is a great pad, but if you want even softer recoil (at the risk of greater wear if the shotgun is pounded on), try Kick-Eez (http://www.kickeez.net/). I can't vouch for them personally (although I have one on order to try them out), but there are rave reviews of these pads on other forums. Might be worth a look.