My experience with their support has been very frustrating. They've never fixed ANYTHING for me.
Similar experience here. Well-engineered products, incompetent or unresponsive support. My impression based on several fairly simple inquiries is that the support reps know little or nothing about the products beyond what is provided to them in a canned problem-resolution matrix. (Outsourced maybe?) In particular, they seem to have no access to information from the product developers about the implementation of the various supported filing protocols.
I use a Drobo 5N as a weekly secondary back-up device for my primary file server, a vanilla Linux box. (The primary back-up device is another vanilla Linux box, which performs hourly back-ups. I use Google "Drive"—i.e., cloud storage—for tertiary offsite back-ups.) The Drobo is actually reasonably configurable as filing appliances go, but I've learned to treat it as a black box: it does what it does. The documentation is primitive, the tech support reps are unable adequately to respond to anything but the simplest of questions, and any customization you perform, even if nominally supported, may be bollixed up by some future minimally-documented firmware update.
As a black box, used as a back-up device, I've found the 5N to be both extremely reliable and reasonably responsive for network-attached storage. But I personally would be nervous about using any Drobo—even a channel-attached local device—as my primary filestore. Because if anything went wrong, you really wouldn't have any recourse.