I use the grunt guts from Al as well and have gotten nothing but rave reviews from the folks who have my grunts. I don't make a lot of grunts and so I haven't put in the time and effort to create my own toneboard. Although, that is something that I'd like to do in the near future. I think whether you make your own or buy the guts, it really comes down to a personal choice. With duck calls, it really can be a heated debate. Not so much with other calls it seems. My thought is if you are pleased and your customers are pleased then keep using the purchased guts. When you feel the time is right to develop your own, go for it.