I bought the polished version and I like it very much. The install was easy (self explanatory).

For those seeking guidance...

1. Pry out the rubber seal with something like a nail and clean.
2. Flip the cap over, and the valved cap innards drop into your palm. Clean this out with a an old toothbrush (don't brush teeth with it afterwards).
3. Pop the valved innards back in, and work the rubber seal that works as a retaining ring back in with the said nail (or similar instrument).
4. Wipe the new cap with a soft cloth, grin and nod in approval.
5. Write a review here.

Rating: [5 of 5 Stars!]