Well, the Spark arrived, a few months after I ordered it on the $50 deal (full-size Spark, not the mini). My conclusion so far is that this is a pretty lovable little pedal, quite a bit like the Timmy in terms of function. You can dial up some gain or leave it clean, boost the signal or just dirt it up and pass through at the same level. Bass & treble controls are flexible & functional, though I'm not sure where they come in the signal path. I'm not sure I actually need it for anything -- it's not so clearly better than the Timmy to get it off my board, and so far the Fat and Mid settings aren't doing much for me. But further experimentation is called for.