Here is a card I bought from Legendary a few years back.
Scan from the auction:
http://www.legendaryauctions.com/Lot...ntoryid=113654
Here is my own scan (after having it swapped from PSA to SGC). Scanned with my Canon Nanoscan 9000F. Completely stock settings.
Clearly, the Legendary scan is quite a bit brighter / more contrast.
Not trying to bag on legendary here - in fact, I have been very happy with all my dealings with them. I was very happy with this particular purchase, and when the card arrived I was 100% happy with it and didn't feel their scan had given me an unfair perception of the card's appearance.
In fact, I think my scan looks quite a bit better, and has greater eye appeal.
But I agree with the basic premise of this thread, which is that their scans tend to lean towards the "bright" side, color-wise.