I am just going through similar choices.
I just bought a stage 2 (revision b) and after a week I was so unhappy with the sounds that it went back.
I want to say up front that I am not a keyboard player, I play sax mainly and have a decent studio with things like TruePianos, Omnisphere, Absynth, NI B4. I have lots of Piano VSTs over the years from NI, Steinberg and a host of stuff with Kontakt and Halion - old school now. I have been using TruePianos Diamond module as my goto.
For the last four years I have been hot-housing myself on keys, playing 3-15 hrs a day - some physical problems preventing me playing the sax.
I also owned an early KeyB which I sold to get the Stage 2. I have a nord electro 2 also.
I play jazz and rock.
I know little about touch for the piano - so I can't deal with this perspective. I learnt piano on waterfall keys mostly (oops!)
I was very eager to get the Stage 2. When I got it home and plugged it into the studio I dowloaded the XL sizes of the pianos and then plugged in the MIDI to my studio.
I was hoping for one excellent piano which I could grow to love. I found a mass of compromises. The keyboard is very well built and the interface is amazingly thoughtful for an all rounder, but the sounds, none of them satisfied me, with the possible expetion of the organs. I think this is due to the lack of disk space, there is simply too many instruments crammed in to too little disk space, IMO.
The Synth section
I own some good VST synths my favorites being Absynth and Omnisphere. I was hoping that, with the addition of the ability to use samples, I would hear Omni like sounds, but what I found was cheesy eighties disco type sounds. Auditioning the synth samples they all seemed to be not of high quality - especially the vox samples - sounding like frebbies from an old computer mag. I think they were all sixteen bit? Maybe you could get this going with some better samples and some work of your own.
The Piano section:
Again, I am not an expert, and it must be said that this is a stage piano and what I was looking for was perhaps a studio type emulation, but I found compromises everywhere. For a start the whole idea of having small medium and large samples is a compromise there can be no doubt about that. The biggest XL grand comes in at 198 megabytes. By comparison the largest offering on the planet is VLS's gigantic offering the Imperial - at 60 gigabytes I make that 700 times larger. Ivory II is 22 gig. I know we are talking flash memory, (and yes there is the question of load up times) but half a gig? For everything?
I wonder how many seperate samples have been used, how many layers, how compressed the sounds were, were the samnples lossy? After playing for hours every day for a week the Stage had to go for this reason alone - the painos. I did not need a synth so this was not part of the equation.
Aurally I could not get on with the paino sounds and found it to be synthy in direct comparison to the TruePianos Diamond Module http://www.youtube.com/watch?v=zsd2SJThgjU.
Touch wise, from my non expert perspective, the keyboard of the Nord seemed to come alive with the TruePiano (which is also small and cantradicts my hypothesis) as soon as I switch back to the Audio coming from the Nord, the keyboard felt singlificantly less vivacious and things like trills became hard work.
The Organ section
For me the best part. until the week before I had had a KeyB mark 1. I also used the B4 VST. I like the B4 for its wide range of cabinet emulations and for its presets. On occasions I used my Nord Electro.
The Hammond on the Nord Stage 2 is well laid out, I would have preferred some kiond of rocker switches to the 'drawbuttons' which arent grabable. I can see Nords point in not using sliders (as the presets would not be reflected when selected), but a rocker switch could be better I think.
Aurally its difficult to compare one Hammond to another as various settings have to be spot on to make the comparison. I have never owned a real Hammond, but I would guess that each beast has its own personality anyways. I ran quite a few tests and found the Hammond sounds to be good but thinner that the other organs I have. This was not too bad, as there were plenty of ways of compensating for this.
The Leslie emulation was quite good as well, certainly useable, I found the fast speed of the Leslie to be faster than I was used to. I search for a setting to slow it down but did not find one, I did find a setting to differ the acceleration speed from slow to fast - the brake speed.
On the Nord Stage 2 there are some different Hammond organs, I selected each one but did not find any marked difference. I only spent five minutes on this ands its possible that I did not discover the right attributes.
I did like the Vox and Farfisa which were to my untutored ears very good. The fact that the organ interfaced provided a close emulation of the original controls, brought tghe epxerience from being two dimensional to three dimensional. I have never owned either of these organs but I found the epxeirence of using them to creat Door's like runs very rewarding.
For me the synth was unremarkable - especially the preloaded examples - nothing exceptional at all. The Pianos I could not live with, they may be all right for cutting through the mix of a rock band ( I would rather have something better) but in the studio (OK its not what its designed for) I could not use it for either practice or for recording. If the Stage 2 had stayed in my studio, then it would have been a MIDI controller for TruePianos.
I think I am going to end up with a Nord C2 for organ sounds and a dedicated stage paino sound as the Roland RD700x or a Yamaha CP1.
If anyone want to recoomend anything else I would appreciate it.