Some scanners have something called Digital ICE built in and can be set for all scans.
I've been using a D7000 with a macro lens, a jig to hold the slides and a soft box to provide the light. From the lens to the jig is a piece of black art foam that surrounds the lens and extends almost to the slide jog. This keeps stray light from entering the lens, especially light from the soft box which is pretty much aimed directly at the lens.
Within seconds I have an image from a slide and can easily shoot 150/hour. I then batch process them though Photoshop to clean (dust & scratches filter)them up and sharpen them, the equivalent of Digital ICE in the scanner. My results are as good or better than the scanner and I can accomplish in one hour what was taking me 8 hours with the scanner.
Then I load them into Lightroom and within minutes find all of the ones I want to keep!