Something I am going to try and I would like to see the experiment duplicated by someone else. I think I mentioned this above, but my D800 files are opening faster in LR 5.3 than the files from my D7100. I have not had my D7100 out since my D800 arrived. I believe I was shooting my D7100 with lossless compression. My D800 in shot with no compression.I am going to try shooting my D800 with lossless compression and with no compression and see how long LR 5.3 takes to render each. I suspect it may take LR more time to uncompress and render the compressed files than to render the uncompressed files. Files from both cameras load very quickly into the LR 5.3 watch folder. The vast majority of the time is spent rendering the files. I will report back in a day or two. I will repeat the process with both cameras with several images.Look forward to hearing from you all.Roger