Had some time to work with this pedal over the weekend.
First off, yes, it can be set to sound very much like the QC capture I had grown to favor. (I gravitate toward the low-mid setting, personally, which is a bit warmer and smoother than the high-mid boost. I suspect the latter is more like the actual treble booster Tony would have been using in the '70s, but the smoothness of the low-mid setting works some magic that would likely have been done in post on any studio recording.) Obviously, it's nice having the full analog controls at hand with the real pedal, but putting it in the effects loop introduces a bit of noise, depending on how much gain I'm adding, whereas the capture is nearly silent.
Plugged into my Mesa Express (the only tube amp I own at present) things are more subtle - mainly because the Mesa has so much gain on tap and so many different voicings of its own. There's a lot of overlap between any given channel dialed in any given way vs. different settings plus the boost (dialed in any given way.) I don't have an old JTM I can dime to hear what the pedal is "supposed to do". It definitely helps with feel a lot - more squish, more feedback, etc. And it lets me add more gain to a channel whose voicing I might otherwise prefer to the Mesa's "Burn" channel. So far, so OD pedal.
I have to chuckle when I watch demos of boost pedals, so many of which begin with, "Here's my base tone, without the pedal on... BRAAAAP." Then they turn the pedal on and it sounds like an amp I might actually buy.
My first response is always, "OK, the boost helps a lot, but WHY (at any point after about 1990) would that be your base tone??"
Anyway, it says Tony Iommi on it, and it's 25% birthday present.
I don't really need it, but I'm going to allow myself one more "trophy pedal" LOL.