I'm very happy with the Opto-DX. I ordered it with a 3m optical cable that allows for physical separation between the M Scaler and DAVE. For a while I used Poweradds, but switched to some Uptone LPS-1.2 power supplies that I had lying around. Everything plugged into an Audioquest Niagara 1200 (which made a HUGE improvement). I also just upgraded the four stock BNCs that come with the Opto-DX to .25m Wireworld Starlight 8 dual BNCs.
I I haven't heard the WAVE cables, but seems it's a great product, too. I'd think about form factor preference: two cables for the WAVE, but a little heavy and unwieldy that might limit gear placement, or box proliferation with the Opto-DX, but with easier cable management and more flexibility on gear placement. I don't think you can go wrong with either solution.
muski