I agree! I have three clean modules; KH1, Tweed, and Blackface, all stock. The KH1 was supposedly modeled after several of Hammet's favorite Twins. My Twin module does not have that clean Fender "sparkle", but both the KH1 and my Tweed module do have it. The Tweed does not have the clean headroom of the Blackface or KH1 modules-you have to keep the gain low to get a nice sparkly clean tone, but it does sound great with the gain below 11 o'clock. I have both an RM100 combo with 6L6 power tubes and an RM50 with EL34's. The KH1 sounds amazing in the RM100, but, inexplicably, it has a nasally cocked wah sound when run in my RM50 with the EL-34's. The Tweed sounds great in both apps and the Blackface, while it does not sparkle like the KH1 or Tweed, dos have an acceptable sound in either amp; i.e., it doesn't get nasally in the RM50 like the KH1.
I assumed the KH1 would be very similar to the Blackface, since they are both based on Fender Twin's, but that has not been my experience...my go figure?