So my background is engineer with plastics molding, and there are a few simple tweaks that could raise this from 2-star status to 5-star status in my eyes. First of all, the cup is very difficult to place on the post. You have to line it up just so. Unfortunately, there's no line or indicator to tell you where to line this up, so you may fumble with it for a good minute before it'll go on.
Would've been so easy to mold a line or arrow into the cup AND base at no additional cost. Once aligned, you'd know it was ready to snap on. Secondly, forget about putting anything with liquid in here, or prepare to be sprayed with it no matter how tightly you hold the lid on.
The lid edge meets the cup edge, and there's no sort of seal or lip, so when I put some stewed peppers in with a tiny bit of water, my walls (and I) got sprayed with red liquid. Good times. It even sprayed a little when making aioli last night, with no water. Would've been so simple to mold a lip onto the lid to prevent this, again, at no additional cost to manufacturing. How'd this get through the prototype phase and get approved??
It chops and blends decently well, but for items that are blessedly less liquidy, you'll have to remove the lid a few times, scrape the solids off with the included little spatula and push them down toward the blades again. Otherwise, they'll be missed and will stay solids, clinging to the cup walls.