Why not Precious Stones?
Don't get me wrong - PreciousStones is a pretty cool plugin because it has a lot of flexibility beyond anti-grief protection. But its anti-grief protection is complicated and rather difficult to use, and tends to vary from server to server. That means you have to publish a user manual for your players, or at the very least, a moderately-large pile of explanatory signs. GriefPrevention educates new players with a simple (golden shovel) message on their first chest placement. When they later equip a golden shovel, they get further instructions. If they encounter any problems, they get a message telling them how to fix it! Signs and instructions optional. :)
PreciousStones doesn't include any reasonable newbie-protection. Making an easy-to-get block project a no-grief claim around it would give griefers a very powerful griefing tool. Also, one undercover griefer can provide overt griefers with lots of blocks with which to grief. GriefPrevention creates only one very small claim to protect a new player, and does that automatically when he places his first chest. Because GriefPrevention claims aren't tradeable, griefers have no means to quickly amass claim blocks with which to grief.
Also, while PreciousStones has a cool economy aspect in that it requires you to gather in-game blocks to create your claims, those blocks tend to get in the way of your actual build. GriefPrevention claims don't restrict block placement within their boundaries.
PreciousStones claims don't extend to the sky. That means a "griefer" can legitimately build on top of your build, not only creating an eyesore, but preventinting you from building there (time to move!). That's why GriefPrevention claims extend into the sky.
Because PreciousStones claims can overlap (with the oldest one taking precedence), if you temporarily remove a protection block in your build, you may find that your build now belongs to your neighbor! That's an extreme sadface moment. GriefPrevention doesn't permit claims to overlap. This not only avoids that particular problem, but keeps maintenance in general simple and clean.