It's making some very strong claims to being private. Other VPNs do all suck and the mixnet tech looks solid, but is it really possible that NymVPN is actually more private than Tor? That's pretty hard to believe even if the team seems legit. Has Tor said anything about Nym or mixnets?
Tor does not do any mixing and so any attacker who observes the user and the final destination can simply correlate the two by looking at timing. Nym disable this by adding mixing (no one can correlate outputs and inputs because timing is not the same anymore). Also unlike what Tor ( where routing is circuit based which means all traffic goes through the same circuit for the same session), mixnet is packet based (every packet goes through a different path) which makes it veeeery hard for an attacker to correlate input traffic to output because now every messages goes through a different path.