Been awhile since I had the nightsky even thought I did enjoy it but i thought it was a little bigger, oh well. As for experimenting. I think you get more out of VP4. You can add 4 different plex delays to make all sorts of cool things, or add 2 pitch blocks and 2 plex delays, or plex delays and reverb blocks and pitch block and a modulation block etc.. Add in all of the sequencer, lfo's, adsr etc. Add in series / parallel routing etc. I'd wager the VP4 would be more powerful and more experimental than nightksy hardware.