Since upgrading to CC I have noticed a huge difference with the import performance. My files off both my Canon and Fuji cameras are taking an age to even show in the import window and then when several minutes later it is ready to import, the import is taking 20 minutes to half an hour with just 40-50 images- often crashing my mac in the process. No issues at all with previous LR 4,5 etc- always had quick import. As a professional photographer and user of LR since version 1, I am massively disappointed with this version- its useless.
Have you updated Lightroom to the latest version that is 6.3?
I would also suggest you to uncheck the use of Graphic Processor under Lightroom preferences > Performance panel and restart Lightroom and then try to use Lightroom.
Please let us know if it helps.