So we are implementing a big and very complete localization management system on my company. The system has great features, indeed, but:

1. We cannot use the browser back button, because it is js and it appears no one cared about it (I am not a js Dev, but you can UAE the back button on my site that has js);

2. It is very customizable, but not intuitive. So you have one million options and you never know where to change what you need;

3. It has a save button everywhere, but most options are saved automatically, so you never know when you need to save. Actually, people from the webapp company use the save button as refresh, once we cannot use the browser refresh button;

4. Combo boxes load the elements while you scroll them, so to scroll to the bottom, you need to keep scrolling several times, waiting it to load the elements;

5. It does not allow you to open more than one tab of it at the same time. So if you need to see more than one information from different items, you need to navigate and wait the loading times to see what you need;

6. Emails are not sent in a different thread. So each action that send emails you need to keep waiting until the emails are sent (sometimes there are several emails sent in one action) to continue using it;

7. They not only store and send back your password by email if you loose it, but, as admin, if I click the button to send the user password to him/her, it keeps a copy of the email with the user password in my sent items;

8. To be able to send emails (they are really necessary), I need to include my SMTP info with login and password. So they have not only the system password saved, but everyone email login and password as well.

I am sure there is more, but I can't remember for now, and we are still trying to figure it out how to back our data, as it appears the only possible backup is their own.