Just got mine a few days ago (EU based). Well built, works as promised. But I find that it mostly works for simple things like controlling lights, tv etc. Most interesting targets use proper encryption (mifare classic for example) so I had no luck accessing my company badge. Mifare Desire data cannot be read properly at the moment it seems, but I'm sure that will be fixed. Fun little tool, will probably end up in a d…
If keys aren't found, you can perform a "Reader Attack" - take the nonces from the log during a sniffed authenticated exchange, place them in a MF32Key tool (there are online versions as well) - and this will calculate the key.
The device doesn't have enough computational power to crack on board (for that you need a Proxmark / iCopy-X) - but the team has roadmapped a tethered mode for performing these cracks.