Both look good in my opinion. I do think however that the flat icons look cleaner than the realism ones.
as designer I like flat, no need more time for make it, but it's depend on our clients, they like flat or realism
When it comes to neatness and simplicity, I would go for Flat design. And right now, designers are adopting the trend of Flat design.
site : http://www.flatvsrealism.com/, it was going to be some well designed infographic, will explain us about flatvsrealism, just have to see it for yourself. Check out
yes, The combination of bright colors and exotic typography has paved the way for unique flat design, is a big part of this design idea, and you can see how popular these trends have become in recent months.
I tend to err on the flat side but then often use very subtle shadows or gradients. I guess we're seeing the pendulum swing to the other extreme right now and maybe find some balance in the next couple of years...
They are both good for different things. It depends on what you plan on using it for. For app icons, I prefer flat design. However when the image is larger I prefer realism design.