Well, finally my Blunderbuss has arrived (50 euros more expensive due to customs... *uck). I'm so looking forward to getting home and plug it ^^
[EDIT] Man, this is as awesome as I expected. I'm not as impressed as when I first tried the Musket, but the Blunderbuss definitely brings something new to the table. As I read somewhere, it's closer to The Smashing Pumpkins' "Tarantula" guitar sound than the Musket (brighter and sharper).
Fortunately, the Musket will still be very useful for me (I was afraid that I'd have to sell it). Having used the Big Muff and the Rat so far, the Musket-Blunderbuss pair seems like a good upgrade. I'd say the two of them sound like (but not exactly) a hybrid between the Rat and Big Muff, the Musket closer to the Big Muff and the Blunderbuss closer to the Rat. I'm so looking forward to recording with both pedals and listen to them mixed
BTW, with Guitar->Blunder->Musket->Amp, Musket + Blunder is not very different from just Blunder. Blunder + Fix'd Deluxe seems more noticeable.