REL Stadium III vs. Stadium II differences?

Does anyone know what the version II to III upgrade
is about for REL, esp the stadium?

Any engineering design changes?
Sonic differences?
Or is this about marketing and $$$?

Thanks in advance.
I would talk to Ambrosia Audio in LA ( They are a long time REL dealer and very knowledgeable and helpful.

I do know they improved the circuitry for changing the frequency cut-off/cross-over. This is the same for all REL ST-IIIs. It makes the REL very easy to integrate. The settings have precise frequency steps in 2Hz increments.

More substantial cabinet (always a good thing), improved amplifier section, plus more flexible hookup arrangements, can hook up high-level input for 2-ch and line level for HT LFE simultaneously. But I agree, call ambrosia and ask.
I also believe the earlier Stadiums had 100 watt amps. The Stadium III is 200 watts. See info at: