A few caveats on my review: I must admit up-front that I am a long-time user - and big fan - of Microsoft Project. I have only been using Planisware for about 6 months, so read my review with my bias and relative short term experience using this product in mind.
I like the integration of resources (people) and cost with timelines. It enables us to better manage capacity workflow and see where spend will occur as activities move around. I frequently use the views for cost and resource to look at monthly, quarterly, and multi-year spend. I use an export of the data to a database to pull portfolio level information to assist in planning.
As I said, I'm still relatively new to Planisware, so my "dislikes" are more heavily weighted than my "likes."
Planisware's website says there is seamless integration with Microsoft Project, but myself and many others I know have not experienced this. Specific fields must be mapped from Planisware to MSP, and we have seen issues with the calendars being different in the two systems.
There is a great deal of "Google" help for questions and issues with MSP. Planisware online help is a black hole - in other words, you're on your own.
When working in very large project plans, it's hard to insert tasks (they seem to end up in the oddest places).
When making changes to tasks, there is no way to know what the impact is - i.e., color coding of the change plus the tasks affected by the change. Overall, manual application of format changes, such as color coding a task or set of tasks, is slow, clunky and unreliable.
Overall, I find the system to be very "glitchy." Using Planisware for live planning during a meeting is nerve wracking, at best. I am accustomed to being able to make changes/updates quickly and see the impact in MSP.
It does not appear to be possible to see the dates of resources and costs at the task level. Sometimes it has caused misalignments between the date of an activity and its corresponding resource because you must flip to another viewing mode to see the cost/resource.
Gantt chart generation is doable, but not great output. I use an export to MSP or Excel for OnePager.
Capacity and cost forecasting.
Have a better overall sense of forecasting, though may be at the cost of some planning accuracy because some prefer to plan in other systems.