I don't see why someone would build a sffpc (aside from being unique?) if this project spark is capable of packing in an 8700k, a 1080, water cooled and a lot of nvme slots with 32gb of ram for roughly the same price as building your own.
And since a 1080 mxm is better than the zotac 1080 mini, it makes this looks more delicious.
IMO, I don't like the Digital Storm setup. That extra black box setting on top of the computer is UGLY and sketchy.
I'd rather see a slim 240 rad/fan combo in the front and a tube/res ran across the top or bottom. It'd only be a little wider, and just a little deeper while being a bit taller than the air cooled desk mini but most likely a bunch shorter than the Spark.
Digital Storm is a premium custom PC manufacturer, like Hennessey or ColorWare. They're not in the business of making price/performance devices but high performance and high quality machines. If you want a more sanely priced mSTX rig, get the ASRock DeskMini GTX/RX.