I installed one in a Pre-Gib Tobias Basic, temporarily, and it sounded pretty close to the original. I thought the original pre was stuffed, so got the replacement, but then discovered a bad solder joint and fixed it up. I can't honestly remember whether the new pre had the treble boost interaction at the top of the mid-boost, as described in the spec sheet, but I imagine it should be the same. The sound quality was fine, in fact, I'm going to fit one to another one of my Pre-Gibs, because it has a weird WTMB Pre that doesn't handle the high output of the drop-shoulder pickups very well.
Actually, you can also get 3 different mid-boost modules to go with the TCT, plus a switchable module, that has all 3 freqs. I bought a few of each, so I can tailor the freq to suit the bass, especially fretless versus fretted.
Pre-Gib Tobiases, Roscoe SKB 3005, Chapman Stick Grand 10, TF550, Berg AE410, Tecamp L212