The EX1R recognized the device but complained the format wasn't supported. .

This is normal for any drive as the camera needs to format it before it can use it.

Have used my unit (with SSD) twice over recent weeks for long form recording with the camera in a single position on sticks.

It was so nice not having to wrangle lots of cards and the offloading was painless thanks to the fact I installed an E-SATA card in my Mac Pro.

I wish I could write something more exciting but basically the unit sits there and does the job. You literally forget it's there.