>I think there should be a (optional) storage container integrated where the ground coffee goes.
There is a little cup that fits right below the grinder, or do you mean something else?
>I would expect a $749 grinder work with any coffee beans.
I totally get this, and I definitely want to make a burr set that works with everything. The reason these don't is essentially because these burrs are designed for something called densification - it's where particles are gradually rounded and amalgamated as they are mixed and tumbled. The cutting path for most grinders on the market today is too short for to see much of this, so it definitely sets this grinder apart in terms of flavor profile and even how the grounds look. The downside is that sticky and oily particles resist that process and expand and start to clog up the bottom of the burr when grinding finely. When grinding for filter, it's fine, but with espresso can require some routine cleanings.