I'm one of the NirvanaHQ users, who are looking for alternatives due to the support ignoring their customers. I'm also a person, who won't ever find a task management system, which will suit me perfectly. But as a software developer I always try to fix some issues by myself :)
One of the features I really like in Nirvana is the comment line in the task view (which can be hidden/shown fully/shown partly). I'm mostly using it for links, so I don't have to open a task to open the link. This feature is not available in Doit.im, but fortunately you keep the whole comment in your comment-icon. So I wrote a quick userscript, which implements this feature. I attached both images: Nirvana and my implementation in Doit.im.

I think, many users would find this feature helpful so consider implementing this one.