I have to admit that after years of using synthesizers now, what I consider a good synth has changed considerably. I used to favor synths that had lots and lots of controls. For me, the more complex, the more menus, the better because I thought that more options would make for better sounds and better music. Naive I know but we all mature musically and otherwise over time.
Then I realized what was must enjoyable about playing music was that it was direct. You play a note and you get feedback right away. On the piano, all the keys are there in front of you. On a guitar, the harmonic relationships are not so obvious but you touch the string itself and in some sense have direct contact with the sound.
Lately, my quest for the perfect controller/'instrument has led me to some fascinating new developments in the musical world. The Tenori-on, Audio Cubes, the Haken Continuum and the Eigenharp all offer a more direct connection with the music. Even DAWs can do the same such as Ableton Live and the hardware controllers that are available for it.
In some sense, while I am sure the average person who knows nothing about a modular synth, would find it complicated to the extreme but I find it more direct than layers of menus. The circuit that is making the sound is right there in front of you behind the panel and the connections are made physically with patch cords. The parameters are not buried in menus but are also right there in front of you to be tweaked. This is what I think made the Minimoog sell so well and why I love my Moog Voyager (ok, it does have menus but you can also just use the knobs to get many of the sounds)
Sound can get amazingly complex with little effort. FM is an example as is PWM. Both of these are not complex technically but the results are astounding at times. Even something as simple as taking two oscillators and then detuning on can create a wonderful effect.
In the end, I think this is why, as some have pointed out to me, that I am moving towards getting a modular synth. Musically, I want to experiment, I want to be the mad musical scientist discovering new sounds by simply connecting cords and turning knobs. What I don't want to be is a computer scientist buried in computer menus.
Don't get me wrong, these have their place and at some point in time I also want to get MAX/MSP and Max for Live because it can do some interesting things. I also will not be abandoning my soft synth collection with its myriad of menus. However, it is the the world on sonic exploration that is a modular intrigues me at this time as do musical controllers.
Right now I'm cash strapped. But in time, I will find my way around to building a modular and finding new sonic landscapes just beneath the surface, not the menus.