Definitely a siphon would be harder to start up purposely. But I think the best strategy toward preventing siltation is to get it while it's suspended, removing the most heavily silted water while the silt is suspended. Once it settles out, it's difficult to dislodge from the bottom and a stationary pipe inlet wouldn't be able to draw it from more than a few feet away. A siphon system will let you buy a smaller pipe to remove the same volume of water during a rain event, unless you go and open the valve during the event.
