I have both of these controllers and a korg nanopad. I found the Korg to be superior to the nocturn, the software of which I found to be irritating because it doesn’t default to sending midi data (you have to load it up to use the thing at all), and it generally felt slightly more flakey to use (although, its not bad, but i think the korg is better). I bought the nocturn because it was the cheapest midi controller with a crossfader on it, which i needed. It is okay, but like i said having to use the automap software even if you just want midi is annoying, and it felt like it would only take so much abuse - i was hoping for something which would allow me to transfer DJ crossfade techniques to midi… i dont think it really does that, for one thing it seems to have a very small delay on the response of the fader, and it feels like it’d come off if you just it with any vigour.
Anyway when i bought these I was basically looking at the same thing: i wanted generic controls not transport stuff, because i wanted it to use with my own max/msp patches. However, I found the Korg nanokontrol to be an excellent solution. This is because you get a lot of faders and buttons for your money, its WAY cheaper than the other devices you’d be looking at, and in some cases it has more faders and buttons than those devices too. Don’t be fooled by the fact it looks like it is designed for the volumes + mutes, solos and pans for your DAW, as it is very easy to assign these controls to anything you want, and crucially there is alot of them. You can also skip through 4 pages of them, that’s what the ‘scene’ button does (nothing to do with ableton live)… so you get 9x sliders, 9x dials and 18x buttons, all of that timed by 4 if you dont mind using the ‘scene’ button. That is ALOT of controls for your money, and its a solid piece of kit. Yes the Korg has transport controls, but you can ignore them, and who knows you might find them useful one day?
You could also buy 3 korg nanoKontrols and you’d still be looking at less cash than some of the other controllers. However the only problem with that, is that you’ll probably be looking at needing a USB hub, and you’ll have USB cables everywhere. It’s annoying, especially because on my setup I find if you swap the USB plugs around, it messes up the devices. I’m actually considering fixing the whole thing with the hub to a board to make it neater and avoid this. But ideally you would just want one controller I think, and if i had the cash i might have bought the bitstream instead. I am not actually convinced that USB is an appropriate way to send midi data if you want to do stuff reliably in a live scenario, and from that point of view the bitstream is favourable because it has both.
The other question i suppose is why faders and not sliders? i guess it depends what you are doing, but i actually think sliders are much better for alot of stuff, you have more swift control; just look at the stuff DJ’s can do with faders - you just can’t do that with pots. The only reason i can see why you’d prefer pots, apart from the fact they take up less space, is for transitions which you want to deliberately be more subtle.
Hope that info is of some use anyway. Don’t forget to consider stuff like that Akai APC40:
it’d blatantly designed for ableton, but those buttons could probably also be reappropriated quite easily.