When I watched Getter Robo Armageddon for the first time, I must confess, I thought it was just okay. Which I suppose, was kind of my fault.
I had not seen anything Getter Robo outside of SRW. I had no idea who these people were, what their backstory was, or what was going on in general other than everything was screwed up real bad for just about everyone. It felt like I was watching GaoGaiGar Final without having seen the original GaoGaiGar. The only reason I didn't check out the previous Getter Robos was mostly due to the fact that 70s and 80s anime wasn't really my thing, and I heard that Armageddon was okay on its own.
I mostly continued watching it despite those complaints for the giant robot action, to which it delivered on that perfectly. Stoner Sunshine and
were some really awesome moments.
But like I said, my enjoyment of it was a bit dampened due to me not really understanding the context of everything very well. I understood that Getter Rays were essentially Spiral Power, but that was pretty much it. It was still a fun experience though.
Also this *spoiler-filled* AMV on it is awesome. Heats is one of my favourite mecha songs of all time.