Of course it comes down to a matter of opinion as to whether it's worth it or not. Everyone's different. But as I said, it is beyond worth it for us. Especially the cat. 1 suites. They are so nice!
BuzzNutt - Do NOT feel bad about being "demanding" - that's what you're paying for! Within reason, of course... but concierge does everything they can do accomodate your requests. We have been given service above and beyond what we expected. The only difference I can think of off the top of my head between the concierge levels is that cat. 1&2 can order off the dining room menus for room service; cat. 3 cannot. Or at least, they couldn't last I knew.
But if you wanna talk demanding... let me give you a link to our pics from last year's cruise in the Walt Suite. We asked them to cater our private party. We thought we were being demanding, and they went way past what we asked for. Take a look at what they laid out for us in our suite!!
http://homepage.mac.com/b.creighton/PhotoAlbum12.html