You need to read back through the past several months of discussion. You'll find more opinions than you can shake a tamborine at.
I've written volumes about how much I like the PSR9000 and haven't changed my opinion. But that's for me. Decide what features you want and go try out the keyboards with a dealer who can answer your questions. They are harder to find than you might think.
I would think the lighter, organ-type touch would me easier on the wrists than weighted keys.
The SK880 seems to be a really good keyboard (haven't tried one personally yet), but it has been around a couple of years I think. The 9000 has some really neat features like programmable custom data base, sampler, vocal harmony and wonderful microphone processing. It's easy to learn and use.
It's a little heavy, but so is the SK880.
None of these keyboards are perfect, but they all are really good. It would be hard to make a bad choice.
If you have any specific questions about the 9000, feel free to email me. It's keeping me from having to get a real job.
Don