SS Hard Drive with Bluesound Node 2

As an experiment, I purchased a $50 Passport, 1TB, solid state, USB drive, loaded it up with all my hi-rez files and about 100 flac-ed cds, then hooked it up to my B/S Node 2. Using the iphone app, it works flawlessly and sounds perfect.

The B/S user manual recommends against using large hard drives at the USB port, and I continue to see streamer manufacturers using mechanical hard drives, avoiding solid state. Any body known the thinking behind this?
Right now, 96 albums, about a dozen of which are hi-rez. I've got several hundred more cds which I'll keep ripping and adding as the spirit moves me. If I run into any issue as the collection grows, I'll post. 

But, so far no access issues nor any file management issues. Some annoyances like: Bill Evans, Bill Evans Trio, The Bill Evans Trio, The Bill Evans Trio at the xxx, organize as different artists, but using JRiver I could manipulate the meta data if I wanted to.
I don’t know if my setup would be of interest to you, but I will share it nonetheless.
I have a BS Node 2, and have a very, very large library of music on two external drives. One is a Toshiba small USB mechanical HDD and the other is an Iomega USB mechanical HDD.
I decided to invest in a 4TB Western Digital MyCloud HDD. This device is not a HDD that connects to a computer, but rather setup as a stand alone storage drive that can be seen on a cell phone, Ipad or computer. It acts as your own personal MyCloud device. On the back of the MyCloud HDD is an external USB that backups my music files to another HDD in case of drive failure.
I have moved all of my large AIFF music files (my whole library of digital music files) to that MyCloud drive and the Bluesound app on my Ipad finds those files and plays them via my home wireless network to my stereo. I was skeptical about how well it would work, but I have a good router and repeater. It works flawlessly and sounds great.
In fact I can play those files wherever I am over my phone by using the MyCloud app on my phone. Conversely, I can send pics or files via a phone cellular network to that MyCloud drive.