Hi @mystery,
I’ve found a few links which should answer your question:-
Summary of the release date for each model. Note, Hardware 2 and 3 are the same > Here <
Datasheet for the Hardware version 1 (other Balance models at the time are also shown). This is from March 2010 > Here <
Datasheet for Hardware versions 2 & 3. This also shows other Balance models available at that time - April 2012 > Here <
The current hardware version is release 4 - the specs for this model are available > Here <
Please note, WAN Smoothing is a new feature available from Firmware 7, therefore this will not apply to Hardware 1, but should apply to the other hardware versions.
Latest Firmware (5.4.9) for HW 1 is available > Here <
Latest Firmware (7.1.2) for HW 2 and 3 is available > Here <
Latest Firmware (7.1.2) for HW 4 is available > Here <
You can also try our Beta Firmware (8.0.0b3)
Hardware 2 / 3 > Here <
Hardware 4 > Here <
I hope this helps,
Steve