I can't comment on it's security, but all of the snap apps I've used have an insanely high start up time that it's genuinely confusing how it could be so bad.

On my laptop with a latest gen ryzen cpu and nvme ssd, the Chromium Snap takes 30s-1 mins to launch, while the .deb launches in under a second. Same for Spotify, Discord and others that I've used. The start up time is so bad that I replaced them all for .deb versions which has been much better.