Maybe Nifty PM isn't there yet, but I'm sure they will get there soon.

It is easy to use and allready really usefull as a project management tool, but would be better if following features would be there:
1. Tasks only have due date, not a begin and end date. Probably not everyone has the same opinion on this, but in my view tasks should have a begin and end date. Using begin and end dates for tasks is more work but gives you better input for realistic planning and a better build up for you milestone begin and end dates.
2. Notifications for tasks should be based on begin dates of tasks not on due date: so you get reminded to start instead of that you are allready too late to realize on time... At least this should be optional to chose between notify on end date or begin date.
3. Ommit weekend from planning. Now weekends can’t be ommited. Ofcourse you can adapt to it manually but this means that if you move a milestone and it has some milestones dependent on it, you have to manually move those milestones out of the weekends. And this every time you change your milestone planning...
4. Possibility to add a milestone directly when adding a task. Now you have to add a task and in a different step/process assign it to a milestone. For an efficient workflow it should be possible direct at the task creation in one screen.

Maybe you are wondering why I give them a five star rating while the above seems like big cons. Ofcourse some other PM tools allready including the above features. For example Zoho Projects and Bitrix24 have nice free plans. But those free plans have some limititations and when i consider how Nifty PM picked up some suggestions uttered via the chat I'm pretty sure Nifty PM will get there.