I have the 870 Express Tactical, but with
Blackhawk recoil stock. Your comments about the pump action was interesting to me, because I didn't really think any thing of it with my own shotgun. Only other shotgun I shot before that was the Benelli SuperNova or something like that, and I thought that action was so super slick? In comparison, I thought 870 was good, but not anything special.
I still like my 870, but I also wished I had looked at the Mossberg more, because its action feels similar to 870 to me, and I much prefer Mossberg safety versus 870. Also, Mossberg 590(maybe also 500) can go 8 + 1, where my 870's relatively low 7+1(w/extended tube on Tacticals).
They are definitely fun to shoot & I hope you find the perfect one for you. Me, I may shop for rifle style stock, or buy a whole new shotgun someday. I've been interested in semiautomatic, also. If Saiga sold for $400, $500 like back in the day, I can see myself owning one of those within a year.