I use a Kawai K-5000 synth. The keyboard has a pretty good feel, but not great. I would prefer something a little closer to a piano (I believe the K-5000 is semi-weighted). It has aftertouch, which is great with some instruments, but as far as I know GPO doesn't use aftertouch so it's not really needed. Extra knobs and stuff aren't really needed for GPO either, but if you use another virtual instrument you might need them. I have an Evolution MK-225C, which has a horrid keyboard, but the controls work fine with Autria's MMV (I would never use it with GPO).
Currently I am using a Kurzweil SP88 and I am semi-happy with it. The weighted keys are terrific, however the ribbon controller is not GPO friendly. Also, the way it handles MIDI zones is not my favorite.
Previously, I had a StudioLogic (Fatar) SL88 and I loved it. It was stolen, otherwise I would still have it. The weighted keys were great, controller wheels were good and I liked the way it handled MIDI zones. The price was right, too. I thought I would be upgrading going to the Kurzweil, I was wrong.
We are the music makers, we are the dreamers of dreams …
24" 2.4 Ghz iMac, OSX 10.4.10, MOTU 828 MKII, 2 Glyph 250 Gig external drives, Logic 9, Finale 2008 GPO, JABB, Strad, Gro, Reason 4, EWQL Storm Drum, Adrenaline, Symphonic Choirs, SO Gold,All Arturia Synths, Many NI Synths, Spectrasonics Synths, KH Strings, VEPro on a Windows 7 4x 2.8 Ghz 12 gig of RAM
In the old and ancient days when computers only had 16MB of memory and a HD space of 400MB, I used a Roland XP-30 and a Technics SX-P30 digital piano.
After GOS came out, I sold the Roland XP-30 to fund the purchase of GOS, which was a stupid idea cos then I didn't have any mod-wheels to use with GOS. So I bought an Evolution MK-225c for the mod and pitch wheel, which also came with 8 knobs and 2 octave worth of keys.
My latest controller is the Behringer BCF-2000 motorised fader surface.
Am I happy using GPO with these 3 controllers??? I think so... I programmed a velocity curve in Logic's environment for the digital piano to suit my playing style and the Evolution gave me the mod/pitch wheel I need... But if I can do it all again though, I woulda sold both the Roland and Technics and bought a Yamaha S80 or S90 (now) or S08 (no money!)... Nicest touch I have found, ever...
I use my Kurzweil PC2-X as my midi controller. Of course, I didn't get it for midi input, I got it because it's 88 keys and weighted (and it comes with a lot of orchestral samples which is really useful for when I want to try an idea really quick with out having to load up GPO).
I use three midi controllers also, in order of how often used
1. M-Audio Oxygen8. I use this a lot with GPO and my laptop!
2. Korg TritonLe (not as good as the Oxygen because Korg uses an all-in-one mod/pitch joystick which springs back into place when not used. But it still works very well, as long as you are playing only one hand at a time and don't mind constantly having to hold the modulation part steady for the dynamic you are wanting.
3. Yamaha Clavinova CLP-560 digital piano. I use this one for doing the piano on GPO and stuff. It is nice to be able to use the whole range, but there are no pitch or modulation controls on it, so you have to go in and do all the editing of that stuff in the sequencer or notation program.
That's it for me.
Not sure this helps.
MacBook Pro Intel Core 2 Duo 2.5ghz 4GB Ram OSX 10.5.8
Korg TritonLe & MAudio Oxygen 8
T3, Logic 9, DP7, K2, GPO4, Strad, Gofriller, C&MB, Finale 2010
Fatar StudioLogic SL-880 Pro - it was both the cheapest and
the best action of any of the 88-key weighted controllers I tried.
Fabulous for playing physical modelling percussive/plucked patches.
It doesn't provide any switches/faders beyond the basic pitch and
modulation wheels, sustain and volume pedals (pedals not included),
but it covers exactly what GPO requires (keys/mod./vol/sustain).