OK, my final review of the HP5:
Love the truer color of both daylight videos and stills. I think the night stills of the HP5 are Brownings best yet for clarity. With video, the HP5 has solved the problem of the slight mechanical "hum" that could be heard in HP4 videos. And it is true that the HP5 has farther night illumination than the HP4 by maybe 10-15 feet. However, to achieve that they have the night flash sort of in "spotlight" mode. This means the center of the image is brightly illuminated to long range, but the periphery of the night images are very dark. The HP4s had more a floodlight night illumination, meaning everything in the image is well illuminated, albeit giving up a little distance. I think the HP5 also solved the problem of deer just beyond the frame of the image triggering the camera.
All that said, personally I think, given a choice, I would buy more HP4s, simply for the better night illumination of the entire image. I do a lot of video over food plots, and I want to be able see every deer in the image, not just the one in the center, even if that means I'm giving up a little distance (and the HP4 isn't bad, I'm getting 90+ feet of illumination). But for close-up work, like at scrapes or travel corridors, I think I would go with the HP5s over the HP4s due to the better clarity, lack of hum, and no deer outside the image triggering the camera.
And if I was doing only still images, I would DEFINITELY go with the HP5. Better night stills.