Which boost was bigger?

[Pocket-God]

Did Piccolo gain a larger power boost from fusing with Kami or fusing with Nail?

Oh and something else I've been wondering, how big of a boost would Piccolo gain from fusing with young Lord Slug?

 

[Let's Go Fearless!]

Definitely Nail.

Chapter: 295 (DBZ 101), P1.4, P2.1-5, P3.1
Nail: “I-I’m astonished…I don’t know what kind of training you’ve done, but you’ve acquired unbelievable power…Still, it’s unfortunate…If you had only returned to the original, single Namekian you were, you might have been able to defeat even Freeza…”
Piccolo: “Are you saying that if I merged with God once again, my power would even surpass Freeza!?”
Nail: “Th-that’s right…I was overwhelmingly defeated by Freeza, but I should have a good comprehension of his abilities…[ ] So merge with me…! I’m also the only fighting-type Namekian on this planet…[ ] That’s right…Your power will become many times greater…”
Piccolo: “…You’re not lying, are you?”
Nail: “If you think so, you can just go get killed by Freeza…”

I don't think Kami made Piccolo over 2x.

 

[sei'taer]

Even if you think Piccolo got some outrageous boost on kaio's planet, you're looking at a far greater boost than when he fused with kami.

 

[Diamond Ryan]

Piccolo went from far below First Form Freeza to making Second Form Freeza transform. Meanwhile, Piccolo wasn't nearly as far behind the Androids. The boost from Nail is definitely far bigger.

 

[Six Trails]

Piccolo "might" be able to defeat (1st form) Freeza if he becomes on with Kami, while becoming one with Nail makes him marginally stronger than even 2nd form Freeza. So the boost from Nail is considerably bigger.

 

[Papasmurf]

Nail stated his being a fighter-type Namekian like it was somehow beneficial to their fusion and that a merge with Kami would only bring him somewhat above 1st form Freeza, so I've no reason to believe the Nail merge was somehow an inferior boost when Piccolo ended up stronger than Freeza's next form.

 

[Evil Vegeta]

Nail boost was far greater.

 

[ahill1]

What everyone above said. Saichoro implied the Kami boost is 2x, while Nail said Piccolo would become many times stronger fusing with him.

Piccolo - 300,000
Kamiccolo - 600,000

Piccolo - 300,000
Naiccolo - 1,500,000

^ That's what I have.

 

[kriss-]

Likely fusing with Nail.