From the alternatives I've looked at, this seems to be the best choice in my opinion, based on features and UI. It also seems to be under active development.
Drawing the full structural formulas is pretty important in chemistry, being able to do that directly on the site would be very useful.
The functionality that we need here would be mostly the full 2D Sketcher Canvas. Some of the additional features that are available might be useful as well, but I think it makes sense to start with only the 2D drawing part.