First of all Falconstor is software (atucally called IPStor).
IPStor software runs on a Linux kernel on a server of your choice. It is esentially a storage management appliance - they call it a SAN appliance. Its has many capabilities. You can attach storage to it and present it to hosts as NAS, Fibre Channel, SAN over IP (storage over IP) etc. It also has alot of added features such as Volume Snapshotting, Replication, mirroring etc. It is a very good piece of software.
A Netapp on the other hand is a Hardware solution. It is a high performance FILE SERVER. However Net App have recently added features that allow storage to be mapped to hosts via Fibre Channel. Nett Apps also have Volume Snapshotting features, Mirroring & replication etc.
It really depends on what you are trying to achieve as to which product you should choose or not choose.
If you post some more information I could give you some more advice.
Cheers