I spent the evening mucking around with my new D1 and it really is a beast. I would say, in some ways, it beats my Voyager for sheer sound design capabilities and it even gives my modular serious competition.
The key is that there is very little to no menu diving. Little things like trigger type, multi or single - that's a menu function on my Voyager but a front panel button on my D1. Which means, it's eminently tweakable while I'm playing.
It also helps that everything is very logically and ergonomically laid out. The VCO section is beautifully simple and accessible, the same with the filter. This is crucial, not just when you're building a new patch but for those mid-song tweak times where you want 32' for a break or need to switch in some nasty digital cross mod.
So far, I've been so spoilt with the complexities of the D1 that I've spent little time evaluating it's less convoluted sounds. But I have worked on a couple of 2 and 1 VCO patches and it does stand up to scrutiny here too. Some synths rely on baroque modulation matrices to cover up what is actually quite a thin and uninspiring sound. Not the D1. Just set up one oscillator, sawtooth or square, filter wide open and you will love that sound.
My favourite patches so far are, however, the batshit crazy insane 3 VCO ones where each VCO is modulated by it's own LFO / envelope and there's FM mod going on and there's filter mod too. With the D1, it's possible to construct buzzing, swarming terrors that ooze and wobble, reel and collapse. But oh so beautifully!
I think this is the start of a great love affair!