Getting the empties stuck in the chamber is an issue with some newer guns, but is usually corrected by a good cleaning and a little steel wool polishing in the chamber. They should not leave the factory that way, but some do.
The metal finish has been up and down. I've seen older Expresse's that look worse than new ones. It seems to depend on which day they were made more which year. Just pass on the ones with bad finishes and pick a better finished one.
If you don't like the wood finish, buy the synthetic. More durable, lighter, and has a better shape and real checkering for a better grip. Same price. If buying wood I also like the laminated better, just cannot stand the reverse stamped checkering.
The plastic trigger group, will probably prove to be an improvement over cast aluminum anyway.
Any of the 870's are a great design. Remington has tried to cut a lot of corners to produce a great gun that will sell at a price that can compete with other guns that cost much less to produce. Sometimes imperfect guns get out the door, but I have yet to see one that would not work great with a minimum of tweaking.