Personally I feel that the idea behind keeping the west/pvp area as an area where you can't bring anything in, nor take anything out - means that people can play in there at a more or less even level.
I thought the idea behind that area was not just about being able to kill or trap other players - but about getting together the resources, making yourself a hideout and praying that you've got enough supplies to survive an ambush
Making it harder to run about killing people - and that being one of the things that keeps it interesting.
If someone is bringing in diamond stuff, tons of arrows or supplies, or using the xp farms to get to 50 so they can enchant something they made in the west - then it's not really in the spirit of the idea behind the area. Especially if you have some people in there not bringing outside stuff in, and some people who are.
Same for ender pearls. With the xp farm, they are so common people are throwing them away because they don't need any more, yet in the wild west they will be very hard to come by - as you'd have to actually kill an enderman to get one. If you can't kill an enderman to get one, then you have to walk everywhere and you can't use them as a quick way to flee someone attacking you.
Unless we run events in the west area, where people can bring in some things - I think it's best to keep it so that nothing can be brought in, and nothing can be taken out.