Can't comment on your points that do matter (as I have not played with Herc for a fair comparison), but considering your points that do not matter - accuracy/green/aesthetic, all which Giant seems to have more weigh, I would suggest Herc for you. If size sways you, then Herc easily. However according to CoRDS, Giant seems to still win on price.

Personally, Green Giant for me. If I had the cash to toss around for a second 3P Dev, I'd go for Yellow Giant.