The img
element works since the dawn of time. Png image support also since a very long time. The other piece of code always needs Javascript, and needs a more modern browser that supports HTML 5 canvas. Some of these advantages may not apply when the usecase is a pushpin in Bing Maps
, since Bing Maps will have requirements on its ownn.
In general performance there won't be much difference, and this may even vary between browsers and versions. Drawing an image is pretty easy anyway (compared to, say, animation), so I wouldn't worry about it.