1. DSM lacks Samba V4 - I would like to have ActiveDirectory at home to serve my 3 Windows machines (roaming profiles) - not an uncommon request!
2. I have two iSCSI LUNs that are defined in my DSM 5.2, but can't be connected to (they disappear in iSCSI targets). I've read the iSCSI problems continue in DSM 6! Data integrity is has absolute priority in a server system, so I'm losing my trust in Synology. One of the main themes on Xpenology forum is "Downgrade from DSM 6.0".
3. QNAP support pages are built much more comprehensible (I'm using the German version), Synology has even problems making clear definitions and explanations of their key words of the system. A lot of the info you need is only found in forums - I hate that! If a vendor can't explain his own system properly and people in forums have to assist in threads like "I think you have to do X and then change the parameter Y, but only possible if you are root user..." - god sakes!
4. What are all the fancy features good for, if a (new) NAS-admin has a hard time even configuring standards?