I have a 30+ year old wingmaster that still shoots as good today as the first day I shot it and still looks great. It has a fixed modified barrel. My two sons both have an 870 express with screw in chokes. The express is not going to be anywhere near as smooth cycling as the wingmaster and the finish is no where near as nice. You are also going to feel more recoil with the 870 that you didn't have with the 1100.
As far as shooting skeet. I took my 15 year old out awhile back to shoot a couple rounds for practice since we had not shot in about three months. I had bought a new automatic so I wanted to test it out. My son grabs his 870 express. I asked him why he wasn't shooting his O/U and he told me he was going to show the old man how it was done. Darn boy shot a 22 and 23 to my 18 and 20. Can it be done? Yep, but not by this old man. But it sure is fun to watch him get so much better than I ever was with a shotgun. Now to just get him to spot me a couple birds.