Thanks for this, I had been wondering myself as to whether to use it. I just got hit with my first pirate attack after having my first paid app out only a 3 weeks (my other app is free with a donate version so no pirates there). So I've been reading a lot about it lately.
I think I'm leaning against using it for the same reasons you state and it's nice to hear opinions of those who have tried it. So thanks for your post
It's hard though -- I have less that 35 purchases and these guys are stealing already. It's pretty hard to stomach as my hope is to pay the rent with app development.