Image preview improvements

Question

Mush as I love lightroom it sure could use a little TLC to improve preview quality and performance.  Here are some of my issues:
Inital import and image culling.  I want to be able to efficiently go through the images on my card and elliminate obvious culls with poor focus and composition.  To do this I need to be able to check them out at 100%.  The import module does this, but there is a problem with the caching algorithm, and after 10-20 images performance starts to bog down and the lag increases to bring up the next image.  PhotoMechanic speeds through the images, and even the windows explorer is faster.
I know I could import them all, render 1:1 previews, and then cull.  That can take an additional 30-60 minutes with an import of 500-1000 images.  Perhaps if we had the ability to view embedded previews in the library module we could import all the images and quickly cull, then build LR previews.  Also, see point #2.
I am continually frustrated by the way previews are rendered in LR.  Occasionally after rendering 1:1 previews some images will not render sharp in the library, even when zoomed to 1:1.  Here is an example of a screen shot of loupe view in the library:
and the same from the develop module:
I have tried zooming in to 1:1 and back and rebuilding a 1:1 preview to no avail.  I had to reload LR to get the preview to render properly.  I see this on a periodic basis.
It can take a long time for LR to get around to rebuilding previews of images that have been edited in develop and you get to see "Loading..." as you move through the library in loupe view.  I frequently have to tell LR to render 1:1, go have a coffee and come back.
I find the same thing on both PC and Mac platforms.  My library preview settings are: preview size 2048, medium quality, never discard 1:1.  My ACR cache is 50GB.  My executables, library and images are all on separate high speed HDs.
With larger imports (200+) it is much faster to do the initial image cull in PhotoMechanic, copy the keepers to the hard drive, and then add to LR library.  It sure would be nice if the image previews performance and quality could be optimized to facilitate image culling and review after editing and at least be competitive with other software.

Answer 1

Hi pangolingo,
Thanks for the bug report and feature request.
We're trying to be clever about the default file type selected when you click on the Download Asset arrow icon. If the layer has a Generator tag, we will respect that, and preselect those settings. E.g., if the layer name is 'hero_01 jpg9' we'd preselect JPG and 90% quality.
If no Generator tag is present in the layer name, we default to JPG and 80%.
We'll consider some smarter defaults - good idea.
Bruce