Easy to use and good results. Plays nicely with other development plugins such as Simple WP FirePHP.
I ran it through the plugin check and all it reports is a slight cosmetic issue. In fact as long as the core has "save changes" as a defined string you don't actually need to change this.
RECOMMENDED: Text domain problems in developer-monitor/settings.php. You have not included a text domain!
Line 49: <input type='submit' class='button-primary' value='<?php _e('Save Changes') ?>' />