Am testing Capture One 10 as an alternative to Lightroom and have become familiar with most all of the adjustment features. But one thing I'm unable to understand is the resolution of the primary viewer panel when an image is sized to fit the panel, at it's lowest zoom setting. The resolution seems low, but when the image is magnified to a larger ratio then the resolution gets higher, which is fine. I would like the "fit" zoom setting to have the same resolution as when being zoomed in, is that possible?
No, not the same resolution, that's not possible. But that's just like in any image viewer that has to resample the original pixels. In order to avoid aliasing and other artifacts, i.e. pseudo detail, resampling in principle always creates more blurry images unless a slow procedure is used to create the lower resolution image. And that's the reason, it's slower to create a good image, and it also often changes the colors of fine detail unless that slower procedure is used.
That's why virtually all these programs use a more quick-and-dirty approach, to avoid long waits.
Having said that, I do think that there is room for improvement. Why not do better than the competition ... But I also know that that will take some serious redesign of the application's code, and they may have several other priorities. One thing they could consider, but it will increase the size of preview files by 50% and slow down other operations, is the use of image pyramids.