Blad01
Smash Lord
An uncharged Boost Smash (BS) kills a little bit earilier, in general ~4% earlier. Here are the exact percentages 
On a side note, if you very slightly charge the BS, you can gain easily ~3%
- Very Heavies -
King DDD : 139%
Snake : 138%
Donkey Kong : 137%
- Heavies -
Bowser : 133%
Captain Falcon : 131%
Ganondorf : 131%
Ike : 129%
Charizard : 128%
Wolf : 127%
Link : 126%
Wario : 126%
ROB : 125%
Samus : 125%
Yoshi : 125%
- Middle-weight -
Ivysaur : 123%
Lucario : 121%
Pit : 121%
Mario : 119%
Sonic : 119%
Luigi : 118%
Ness : 118%
Lucas : 118%
Diddy Kong : 118%
Marth : 117%
Toon Link : 117%
Ice Climbers : 115%
Falco : 114%
- Light -
Pikachu : 111%
Peach : 111%
Olimar : 110%
Zelda / Sheik : 109% (ôO)
Metaknight : 109%
Fox : 107%
Kirby : 106%
Squirtle : 103%
Game & Watch : 103%
Jigglypuff : 97%
On a side note, if you very slightly charge the BS, you can gain easily ~3%
- Very Heavies -
King DDD : 139%
Snake : 138%
Donkey Kong : 137%
- Heavies -
Bowser : 133%
Captain Falcon : 131%
Ganondorf : 131%
Ike : 129%
Charizard : 128%
Wolf : 127%
Link : 126%
Wario : 126%
ROB : 125%
Samus : 125%
Yoshi : 125%
- Middle-weight -
Ivysaur : 123%
Lucario : 121%
Pit : 121%
Mario : 119%
Sonic : 119%
Luigi : 118%
Ness : 118%
Lucas : 118%
Diddy Kong : 118%
Marth : 117%
Toon Link : 117%
Ice Climbers : 115%
Falco : 114%
- Light -
Pikachu : 111%
Peach : 111%
Olimar : 110%
Zelda / Sheik : 109% (ôO)
Metaknight : 109%
Fox : 107%
Kirby : 106%
Squirtle : 103%
Game & Watch : 103%
Jigglypuff : 97%