I made a tangent thread in the Trek Tech forum on this interesting topic. It seemed to deserve its own thread, titled "Moving Slow at Warp Speed". Thanks,Also interesting is that while they are in the solar system at high warp speeds they are actually going very slow. So it would seem that regions of higher gravity actually produce slower actual speeds. This would also match what we see in First Contact, where the Phoenix barely makes any distance even traveling at warp 1. My theory is that warp factor(speed) isn't necessarily directly related to speed but is more related to power put into the system. For example the Phoenix only broke light speed in terms of generating a 1 Cochrane warp field and would have been traveling at 1c if it was in open space. But since it was right next to earth the Actual Speed was less than 1c.
Henoch