Ableton. Warp from here or at BPM

When warping in ableton, say you got a tune that is 130bpm is it best to 'warp from here 130bpm', or 'warp from here straight'? And what is the difference between the 2?

Thanks

i always warp straight, it just assumes there is no swing in it. then i go back an manually correct. the manual probably has a better way of putting it. i just remember reading it and saying, 'this is what i'll use for djing tracks' lol