All ELOS Diamond series tanks are made of their proprietary Diamond Glass on ALL panels since their tanks can be used as a peninsula as well. Wouldn't make sense to have it only on one panel.
I agree the QD2 does look more refined than the QD3. I guess it's function over fashion, I rather have a better performing Quiet Drain than one that looks better.
Watch some recent YouTube videos, you can see some of the newer tanks with the QD3.
Yeah, back in the day, the Diamond series had just been announced, and it wasn't clear if the tank I got (elos 120) was Diamond Glass or not. I got so many different responses from ELOS at the time, and it was a mess. It seemed like a scam to get me to purchase some old stock at a premium price to be honest. I guess I couldn't tell the difference at the end of the day, but it didn't sit right. Fast forward 10+ years or whatever, and again I'm not even sure what I have, lol. I hope everything works out, which I believe it will, but it is crazy that for the price I paid, this is what I'm getting. About 3x more than a similar Waterbox/Red Sea.