Just my opinion, but it seems like a lot of cash for what a 20 buck pen knife can do. That's what my dad used most of his life and it seemed to work fine for him. Me, since I'm new to pipe smoking, got no cake to speak of! lol!
i dont use one (i'm having trouble GROWING cake, never mind trying to keep it down) but i'm intrigued by the idea. i've got a small utility knife i made that i consider part of my pipe kit because i edited it for cutting tobacco (sg black xx twist was givin me issues) so now i'm thinking i'll make another knife, this one for the reaming... i don't really do folding knives, but i bet i could do a nice little straight blade with handles made out of briar to match my pipe
I personally don't like cake in a pipe; I think it makes for a wet smoking pipe, I can't get enough tobacco in the bowl and I think too thick a cake imparts an off taste to the tobacco. I accept I am a minority of one in this!
I've had the same knife now since 1968 - it's a French Opinel locking clasp knife which a plant fitter ground round at the point for me so that it would fit into a pipe bowl. I dry ream my pipe bowls after each smoke with a wad of tissue and at night when cleaning that day's pipe I lightly run round the inside of the bowl with my knife.
I also confess I use a finger as a tamper and tend to knock my pipes ( other than my meers ) out against my shoe heel, fence post, tree, telegraph pole or whatever!