Even worse, the RPi is extremely limited in I/O capabilities, with only a single USB2 hub shared between the 100Mbit ethernet and 4x USB2 connections (including your harddrive.) This means that any file transfer is limited to 10-11 MB/s in the best case... We can only hope that a RPi3 will with USB3 support will materialize before 2020.
I am running a RPi2 as a home server / NAS / VPN / seedbox, and it works - as long as you set your expectations right.
Finally, note that the RPi kernel stack is always slightly outdated due to out-of-tree patches. Most ARM SOCs suffer from this problem, and the RPi foundation is slowly taking steps to fix that after years of user pressure. However, I have decided to switch to a low-power x86 CPU with a fully open linux stack for my future home server needs, until ARM decides to fix their driver mess.