I have in my studio a Rhodes Mk.1 stage piano 88 and also an Alesis QS8.1 that I use to control giga.
I greatly prefer the feel of the rhodes. The key action is lighter, but slower on rebound. Note it's not that spongy/springy synth action I am looking for... Those of you with a Rhodes will know what I'm talking about. The QS8.1 on the other hand feels heavy and stiff. In fact, I have to say the QS8.1 and most weighted-action controllers I have played all feel much heavier than a "real" piano to me... but my "piano feel" is tuned to old Steinway grands and uprights which to me feel much lighter to the touch than, say, a Yamaha. The Rhodes feels much more like an old Steinway to me than a typical modern weighted controller does.
I hear the key-action in the QS8.1 is made by Fatar and is probably similar to the popular SL-880 & etc... most 88-key controllers I have played have this similar stiff, hard feel to them, regardless of manufacturer. I recall 10+ years ago playing a Roland RD-1000 that felt a lot more natural but those are rarer than hen's teeth and weigh as much as a real piano (not really). There's a beat-up RD-3000 that a kb player at church has, it has a similar weight to the keys as the Rhodes but they are much too fast.
So is there any modern keyboard controller out there that feels like a Mk1 Rhodes? Or a used/old kind I should look for?
What about using a midi controler in your Rhodes?
I use one in my Mark 1 stage 88 to perform on stage with Rhodes AND piandsounds- perfect! It is called "QuietTime" but I think you can get one from YAMAHA too.
Hope it helps.
It's a long time since I played a real Rhodes, So I don't know about that, but I might be able to help anyway.
I know exactly what you mean about the Fatar weighted action. They are pretty realistic, but the heaviness can really get in the way for some purposes.
I have owned an SL880 for some five years now. I recently replaced it with an OBERHEIM MC2000. The action wasn't actually the issue - I needed something with much more MIDI functions for my live setup, and the Oberheim has them in spades.
But it also has a much lighter action. It's still billed as a weighted piano action, but it's much less hard work than the Fatar. I find it much better for playing organ-type sounds on, and still resistant enough for a decent piano touch.
The MIDI spec is awesome. I won't go into the details here as it's not what you asked about, but feel free to ask and I will. Or just look it up. It also has a bigger brother, the MC3000, but I think that has a heavier, more weighted action.