I've been going crazy trying to scan transparencies for a long time, and always with mixed success.

I use a Microtek i800 and Silverfast Ai Studio.

If I scan in 48->24 bit or in 48-bit, I can get much more accurate color rendition from my slide. But I get absolutely horrid highlight and shadow detail.

On the other hand, if I scan in 48-bit HDR, I get all the shadow and highlight detail I want most of the time, but the color is terrible and nearly uncorrectable in PS.

I've found Astia to be the hardest to scan, but all slide films I've used (Velvia, Fortia, 64T) have had the same issues.

I've had the Canon 9950F with SilverFast. Scanning with SF delivered colors way off the originals. ScanGear was slow and lousy, so I sold the Canon and bought a Coolscan without SilverFast. Now everthing with NikonScan is absolutely perfect.

In short words: I've had only bad experiences with Silverfast.