Difficult question to answer, really, since they're very different designs, but I'll take a stab even if I'm a little late to the party on this thread. For what it's worth, while I haven't picked either of these personally, neither is in the 'unpickable' (yet) category, since picking tools for both do exist, even if they'd tend to be custom jobs or only sold to government agencies. Each is definitely advanced enough to require purpose-built toolsets (as opposed to general-purpose picksets). Without getting into specifics, the YouTube videos linked below demo the use of custom-made picking tools for both of the specific locks you mentioned as proofs of concept. The Medeco biaxial might theoretically be easier given there have also been demos (e.g. by Marc Weber Tobias) of bumping and impressioning attacks against it -- I'm not aware of any similar successes against the Keso 4000, but that doesn't mean they aren't possible, or haven't been done. Technically, the Medeco biaxial has also been superseded by newer models, so the company doesn't necessarily consider it the state-of-the-art anymore, whereas the 4000 appears to be one of Keso's latest offerings. Hope that's helpful.
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Medeco biaxial: https://www.youtube.com/watch?v=PMZWQP8N-5o•
Keso 4000: https://www.youtube.com/watch?v=hNWNeuFvE1o