What changes will there be in Vanguard compared to the beta?

Well, it’s obvious that this is a full-fledged game with a lot of content, but let’s see what they’ll fix/change:

Many visibility improvements:

• They will change essentially everything, from smoke and muzzle flash during shooting, raindrops off the face, to bugs, and so on.

Many sound improvements:

• Everything there as well: footsteps, general sounds, fewer commentator lines, and so on.

Spawns:

• They fixed those too, addressed bugs, and will continue to fix them later.

Movement:

• Grenades no longer slow down movement, less suppression is in effect, and sprinting time has been altered.

New perks:

• Ninja – dead silence, but as a perk. Dauntless – a perk that removes all slows.

Weapons:

• Shotguns have become deadlier.
• Many weapons had their effective range and hip-fire adjusted.
• Negatives in modules have increased.
• Smoke grenades hide players from afar but not up close.

Killstreaks and field modifications:

• You won’t see allied UAVs and so on hovering above your head anymore, only their effects.
• UAVs and similar are easier to shoot down.
• and a lot more.

You can read all the changes in detail at the source link above.