Cool site !
1. Maybe give the paperplane a little more room to breath in the circle. Either make the outline a little thinner or the circle bigger.
2. On retina the Logo is not crisp.
3. On the Slider, the text jumps when you change the words. Because of “text-align:center;” this is anoying. You need to find a diffrent solution here!
1.Some letterspacing for the headlines on the footer. Small fonts in bold look so squished togeither. Or make them just a medium (500).
2. Have a look at the kerning of your logo.