Which do you think is better and why?
I would go with Ethereum because it's the more well-received in the market, and it's the pioneer amongst these two coins that share somewhat the same technology and background. The only major difference with these coins is that Ethereum was developed in the US, and NEO was developed in China. NEO was even dubbed as the Chinese version Eth at one point, therefore, I side with Eth because the pioneer usually leads the copy; I am not saying that it's because it's made in China, but the fact that Eth has more experience and it commands more support from people.