Go Nagai was only the co author, Getter Robo is the brain product of Ken Ishikawa, if you read his other works like Makai Tenshou and Kyomu Senki then compare them to Getter Robo, and other stuff by Go Naga you will find out the clear differences, for example for once there's not a transsexual character with a crush on the protagonist, i am looking at you Devilman and Violence Jack! (Which are supposed to be part of the same story according to some)
to answer acradius...
I am a Getter Robo fan i started watching only last year but have seen every version.
Thanks to you and SRW.
The only problem i saw was the music why didn't you put in "Heats"?, but thats really not that important anyway.
In so many words...
I love Getter Robo...
in SRW since day one... Freakin A... 5/5