i think tinkering with blanks is just a further progression of the sport. you start of buying factory rods/reels/plugs, and then you see what you can do to make things better. add weight to this lure, drill wash hols in that reel, build your own rods, etc... then you get really into making your own rods and you want to make a rod for everything. how else to make an "in between" rod than really MAKE it in between. give me a hack saw for rod building any day.
