This is a great add-on, but there are a few features I find that vim has which I would like this add-on to have. First is the ability to copy/delete multiple lines, using {i}dd, {i}cc, {i}yy, or any other command that allows you to do something to multiple lines. I find these really useful, and it's kind of a bummer that this extention doesn't support them. On the other hand, at least it supports {i}k, {i}j, {i}h, and {i}l (navigation), which is at least a lot better than just using arrow keys. Overall I'd say it's pretty good, with some minor possible additions.