If you click on Gallery to the left, in red, you'll find several sharp photos I've taken with the HD 55-300 and K-3 at 300mm handheld (I've also posted JPEGs of the original DNG files, which I developed with Lr 5.3, on Flickr under wayneguyb). If that degree of sharpness is enough for your needs, then no need to worry re "zooming too much." Of course the 60-250 would be even sharper, as many have noted here, though only up to 250. You can compare the resolution figures for the two lenses at photozone.de. What you'll find is that on a scale with a maximum of 2350 points, the best center resolution of the 60-250 is better than that of the 55-300 by roughly 200 to 300 points, and the best border resolution is better by roughly 100 to 400 points, depending on FL (the difference increases at higher FL). You'll also find that even at F4, the 60-250 betters the best center resolution of the 55-300 (at F8-F11) by roughly 50 to 100 points, and the best border resolution of the 55-300 by 20 to 300 points (except at 60/55mm, where the best border resolution of the 55-300 is better than the F4 border resolution of the 60-250). So in absolute terms, the 60-250 has a good deal of extra resolving power compared to the 55-300 at all FL. In addition, the 60-250 allows you to shoot at even F4 and still get better resolution than the best the 55-300 can give you at even much higher F stops (with that one exception). Personally, I've been happy with the center performance of the 55-300 (both old and new HD) at 300mm, and also find it has excellent contrast. But the 60-250 clearly offers greater resolution, and all that being able to shoot at a much lower F stop entails, as well as other features that the 55-300 lacks, albeit for a much higher price and much heavier weight. As I noted earlier, I've recently ordered a 60-250, and if my back can manage the extra weight and bulk, I plan to keep both lenses, using the HD 55-300 (right up to 300mm!) as a lightweight travel zoom, and the 60-250 for those days I feel up to carrying it and want the best possible IQ in a Pentax zoom.