As far as I am conserned Enduro is the finish for me. It dries hard, is fairly easy to apply but best of all it does not stink and make me sick like ca does. I also believe that, like Tom said it magnifyes the grain so if when you have that special blank with outstanding grain it just jumps right out at you. Once you get the hang and get just the right amount of sanding sealer and Enduro then it has a nice feel and it does not discolor or darken lighter wood.
If you stop and think of the work that goes into making a nice pen, all the time that it takes some of us to pick out wood for a kit then doesn't it make sence that you would want to take your time and give that pen the best finish possable. In my opinion, when it comes to any woodwork what makes or breaks a piece is the finish and the hardware. I also make jewerly boxs and when I go into a store and see a beautiful box and then open it and see cheap hinges I just cringe. I use 24K plated brass jewerly hinges on all of my boxs so why should I do anything less to anything else that I make. My Grandfather told me many times that if its worth the time to do its worth the time to do it right. I try to keep that in mind.
Wayne