Steven,
The Korg drums are as good as it gets. If I had to rate all three it'd be in this order:
1)PA80/Ketron
2)Roland VA
3)Yamaha
4)All the rest

As for patterns - I prefer the straight-a-headness of the Yamaha to all the rest. The XD9/SD1 sounds terrific, but they still have a weird way of advancing the variations. Sometimes (within a style) A is best followed by C and B is best followed by D. You can't just step through at a graduated pace like on the Yamaha. Korg is at fault here too. Too busy, too incoherent.

Of your three choices - I've owned all but the 7000, and I think as an overall package, the 9000pro is the best.(feature wise)
The absence of speakers (9k) makes the PA80 my next choice. The kn stuff will never be in my rig unless major drum revoicing is done, and the simple chord fingering is changed to include a basic "root" plus "third" = chord. None of this weird "one black to the left is minor" stuff. I hate the thought of using three fingers all night - it's not the way I learned, because I usually play the bass manually. Lately, I've been playing live bass and triggering the arranger with the right hand a lot more. The XD9 calls it "Bassist" feature, and the Yamaha can't do it, from what I've seen. Chord recognition is only dedicated to the left hand, I think.

Too bad you can't get to try them all at once .... they are all very good keyboards, in their own right. My impression of the 7000 suggests that previous owners will be glad to shell out the cash for this new model, based on the USB, SD card, and overall LOOKS and power of the sound.

For a plare that was used to working with quality synths in the past - the 9k is a dream machine. Tough, rugged and loaded with playable features that really WORK.
The PA80 is about midway between the two. It's powerful, and sounds great, but the feel is not as solid as the 9k, and the "glitz" of the 7k is missing. (silly stuff like multi pads that play phrases.) However - NONE of the others has a better sequence player than the Korg - Two independant sequencers - flawless operation so far too.
You've got choices, my friend - but it's better than NOT having any, right?