And by the way, another pro-external reason that I just thought of the other day... With local RAID arrays (LUN's) there's no way that I've found to report the status of the array automatically, should it fail. I have to rely on manual physical inspections today. The QNAP has features for this. Would be a nice thing. HP servers flash and mane sounds, but next time I buy a new server I can go with a supermicro server (that doesn't flash and make sounds) and save 2k 
No I'm not working there, just happen to know they are cheap 