- Session does not require phone numbers, which is Signal's greatest and well-known weakness and has led to a lot of (police/stalker) harassment
- Session uses some form of onion routing, and the messages arriving while you're offline are stored for a certain amount of time (TTL) by "Oxen service nodes" ; no centralized server controlled by Amazon & other evil corps relying on Intel's SGX "secure enclaves" (yes, that is actually Signal's threat model lol)
- Session appears to be involved with the Oxen blockchain where you can pay for a global username to be registered to your public key; i don't know if there's recovery mechanisms if you loose you key/device, but i do know it took me only two clicks from homepage to reach talk of blockchain and tokens and that does not inspire me confidence
- Session claims loud and clear to be developed by a non-profit and to be user/UX-oriented, which is great! Signal's finances and decision making have never been very transparent, and interviews published here in the past year implied they needed more users in order to monetize the platform (how?)