Looking to get back into the Omega to archive streams and the like - assuming I can only use USB attached storage - whats the general experience with HDD/SSDs used on the omega?

Is there a limit to the current draw of the device via the USB port?
Will any USB storage work in the same way as a flash drive?

Thanks!

There is definitely a limit to the current draw on the USB port. If you're using a HDD, the current supplied by the Omega2 USB port will likely not be enough to power the drive, so you may need to use an HDD with a separate power supply.

In terms of USB storage in general, you may not get crazy good performance since the Omega's CPU is meant for less work intensive use cases.
See this thread for more details: https://forum.openwrt.org/t/dir-505-usb-hdd-max-size/60353