But I keep seeing posts from people who cannot upgrade their ERX to latest firmware, because there is insufficient space on the ERX. It seems to me the ERX shaved $1 too much off the hardware cost, and put out hardware which is just a bit too limited in regards to maximum image size.
And, IIRC, the storage is not replaceable (unlike the ERL/ERPOE where you can bung in a replacement (and larger) USB stick).