Like you, I'm interested for opinions of knowledgeable members. I followed the project's beginnings a few years ago.
SPN is inspired by Tor, it gives you multiple IP addresses and you can use a different IP for each service, it's an interesting project, but I've never tested it myself and I don't know exactly what threat model it for, nor what it's supposed to mitigate.
Some will choose Tor for an obvious reason, but the Tor browser and the Tor network have their drawbacks.
I don't generally agree with phrases that say you don't need to trust, I think that's wrong, you do need to trust someone, even if that need could be greatly reduced, otherwise we wouldn't be doing computing.
Mullvad Browser combined with Mullvad VPN certainly improves online privacy and that's what I use.
