I like sd1 on marshalls or fender bassman, oranges...
But on modern amps like rectifier, 5150...it just sounds scratchy and harsh on the highs. It's not bad, but definitely harsh compared to the ts.
That said, I use the sd1 live, while for recording, I prefer a normal ts9.
P.S. engls are supposed to have a extra gain stage so the ts is not needed, or at least I've read that here.