The so-called RAW from vuescan is not really raw, whatever that means.. I guess.
It's a tiff file that Vuescan can open and other things too which fool with that sort of file.
I like it because I can scan a roll of slides, turn the scanner off to save the bulb, then go back and use the raw files as the source in vuescan, messing with the crops and curves, saving them in various sizes etc.
To me it was worth it, even if some may scoff at the file just being a TIFF.