The fans failed and they expect me to send them my hard drives to get a replacement or secure a replacement ( over $1K) with a credit card.

but I also wanted a device that could be left on 24/7 without noisy fans

The MyCloud runs a bit warmer (44-46 degrees Centrigrade, versus 36-39 for the ReadyNAS), but its fan is much quieter

The issue with this product is control internal fan

No fan noise

It ran very hot, and gave me warnings that the fan was not working

Occasionally the fan is VERY noisy, more than once I've wandered the house looking for the source of the noise.

Buy if you want to have overheating issues (fan wont start and have to manually force it via SSH)

Fan can be a little noisy when under heavy use.

The array's cooling fans are loud enough to prevent the enjoyment of music or movies in the same room, particularly as they cycle up to maximum speed for 10 minutes or so out of every hour

In the two weeks I've been using the WD Diskless My Cloud EX2 Ultra, I have only heard the much quieter fan once when at high speed during initial setup

A few firmware updates later and the fan stopped working immediately after one of the updates.

Cooling fan failed after just 4 months , not good for what is supposed to be a high quality data critical device.

The array's cooling fans are loud enough to prevent the enjoyment of music or movies in the same room, particularly as they cycle up to maximum speed for 10 minutes or so out of every hour

WD also has a very good reputation for the quality of their hard drives, as well as for customer support.

Just got this NAS to help me backup my photography as well as give me access to all my files on the drive while away.

I have since ordered 6 more for various clients as well as for internal use