I'm currently using an 34 HP 3TB drives with an array configured for Raid 10 ADM (every drive set = 3 redundant drives) + 1 spare. Drives are sitting in 3 d32600 DAS boxes connected to a P822 controller in an HP DL360 g8 running Windows Server 2012 with a single 30TB share. This volume has about 30 million files that are accessed daily for a period of 1 - 3 months by 25 people before the data is archived to offline storage. Server is a stand alone bare metal installation.
It's important to be cheap, reliable & easy to manage as possible if I get hit by a bus. The only way I've found to do this is ride 1 - 2 generation old enterprise equipment (HP is what has worked well for me). Everything I've purchased is used (except for drives).
I am happy with my Windows + HP situation & 48TB would be fine for the next 2 - 3 years. Unless there's a big risk I'm just not factoring in. When I was asking for advice before & moving from an inherited 18TB / Raid 6 setup on Spiceworks a few years ago several people mentioned a possible concern about large NTFS volumes. Have any of you used 48TB Windows volumes? Any resources on risk analysis vs ZFS?