Why are sliders more popular than dollies?

[ironpony]

I was thinking of buying a dolly or slider possibly, but everyone seems to tell me slider and most other filmmakers seem to have one compared to a dolly.

Now the obvious pro of a slider is it's quicker to set up, where as a dolly, if you are just one a man crew, you would have to make more trips back and forth to the car, to get the equipment out.

However, the thing that worries me about a slider is that you can only do straight movement, and do not have the option of curving. Or if you want to get a curved slider, then you can only do curved movement, and do not have the option of straight. Where as a flex dolly track, can bend and made the shapes you want.

Another thing that worries me about the slider is that it's much more difficult for the track to not be seen in the shot, compared to a dolly, especially when doing push ins or push outs.

So it seems that the slider has one advantage, set up time where as the dolly has two advantages, not seeing the track, and being able to make track shapes, rather than having to settle for curved or straight only.

So what do you think? Are sliders more popular for more reasons that I am not seeing?