Snap is a little intimidating compared to Scratch.

It's clearly designed for older students, but at that point some of the advantages of blocks are lost.

Most of these systems suffer from the 'canvas' model, where you have many stacks of blocks scattered around the canvas as they are created, possibly in no particular or logical order. It's difficult to find things or to get a good overview, and really becomes a navigation problem as projects get bigger. I think they would greatly benefit from a more traditional ide/file type structure, or some other way to structure 'stacks'.