I only played one Samus main ever at a tournament, Hayato. I won, But it was very tough.
You have two choices with Din's.
1st - Destroy Samus' projectiles, Din's is large enough to destroy any projectiles that Samus has shot at you.
2nd - Attempt to destroy Samus' projectiles AND damage samus, this can be risky since if you fail you are probably gonna take some damage, but I seemed to have some success with this strategy. This also means that you want to be farther away so you can have a larger Din's hitbox.
Recover mostly by sweetspotting the edge, you don't want to get dair'd by Samus.
Samus seems to have a hard time killing in this matchup. Not so much Zelda who I feel has a hard time dealing damage.
Samus' UpB is good and once you get hit by it I think it is unpunishable.
I would say 55-45 Samus. The projectiles are not too bad, but the stray ones that hit you certainly add up, and Samus can usually keep you at bay with projectiles once you actually have done enough damage to her to kill.