I just started going to my local RD where they stock Stanislaus and 6 in1 along with others. I decided to do a taste test with these two and a can of S&W I had laying around, all crushed tomatoes.
I knew which bowls were which but my wife or children did not. All samples were straight out of the can with no seasoning.
Tomato Magic was hands down the favorite. My 19 year old daughter chose S&W but the others chose the TM. NOBODY chose 6 in 1.
Having said that, my wife really loved the 6 in 1 I used on the Malnatis DD earlier in the week.
IMO, they were all pretty close (I really thought the S&W would get killed). If all properly seasoned, I think it would be too close to even matter.