The Gentle Typhoon is better IMO. They are both very quiet, quality fans. My observation is that the Noctua has some vibration problems. In free air, it's just as quiet if not quieter than the Gentle Typhoon... that is until you attach it to something. Then the vibration of the Noctua is transmitted to the case and causes some nasty resonant noise. Although Noctua includes soft mounting grommets, I don't think they will overcome its tendency to resonate.
The Gentle Typhoon also resonates, but it's easier to mitigate than the Noctua
The Noctua's are great fans for your heatsink Meaning for your H70. As for case go with the Gentle Typhoons. The Gentle typhoons are more for case fan purposes. As for heatsink fans I think that Noctua's do a better heatsink job. They have a better static pressure than the Gentle typhoons and also are still very quiet. (there NH-U12P SE2 heatsink proves that) The Noctua's also have a higher CFM at a somewhat low RPM. However the Gentle typhoons just have a high rpms but moderately low cfm.
So to sum it up, I'd go with the Noctua's for heatsink and gentle typhoons for case fans.