Maybe I just got lucky but I've actually been really impressed with the amount of detail it picks out with models as small as 50mm in height.
I've used the David software too and didn't see any higher quality with that although admittedly I only used a cheap webcam.
David is way more configurable and you can use professional grade DSLR cameras with it if you want really high quality.
Personally, I prefer the simplicity and ease of use of the Einscan.