I've been using Simple Tagging (yes the predecessor of Simple Tags) since the very first version of the plugin. It was great, saved my time by simplifying the tagging process, thanks to the mass-tagging/auto-tagging feature. However in recent months, I'm not sure whose fault it is but since the Zemanta API support is introduced things are not as pretty as before. I like Zemanta and I use it a lot since it was implemented in wordpress.com, thus I installed it on my self-hosted wordpress blog as well. I know Zemanta has their own plugin for wordpress but since I'm after Simple Tags' mass-tagging/auto-tagging feature, I thought it would be a good idea to just use this, but it seems like I was wrong.
It happened to me before that when I attempted to set Zemanta API in Simple Tags setting, it caused a 404 Not Found error in my blog. It was a terrible experience to me that I was unable to blog for months until the restoration process completed. Then a few days ago, it happened again and I give up. Lucky I already know how to deal with it now so it was not as disastrous as before.
After experiencing all this it's hard to recommend this plugin to anybody, despite the awesome features it has. I don't really mind if the mass-tagging/auto-tagging doesn't work but I don't want other people to face the same thing as I did. That's why I have to say goodbye.