Loading the program is slow. Changing directories is slow. Opening files to edit is slow. The dropdown menus sometimes don't work, or disappear while you're mousing over. Copying and renaming files is slow. It auto-indents SOMETIMES (but sometimes it doesn't feel like it), and sometimes it's 2 spaces and sometimes it's 4. If you try to backspace and prevent the indenting it assumes you're making a mistake and SOMETIMES redoes the indent for you (but sometimes changes from 2 to 4)
The auto-logout feature doesn't work right, so be sure to unplug your telephone and hang a DO NOT DISTURB sign on your front door. After 2 minutes of inactivity it locks the page and gives you a popup that says "CLICK HERE OR I WILL THROW AWAY EVERYTHING YOU ARE WORKING ON". If you don't click in time, it completely logs out without saving anything. If you DO click on time, the page is locked and you need to refresh the page without saving anyway.
This is not an acceptable alternative to webftp. If security issues with the old webftp are too great, then just don't offer anything. I'd have been happier being told that an acceptable alternative doesn't exist and using my own FTP program then handed something that doesn't work well.