I like the product alot but as others have said the price is a tad high,as for the suggestions of some kind of clamp to hold the speaker i cant see that being a good idea for the long haul,i would think that in order for any type of clamp to have enough grip to hold the speaker it would require some serious ft pounds of torque & that cant be good for the speaker cabinet.
I personally like the inserts alot,however i didnt see any mention of a template to install the inserts,with a template & instructions of how to mark the holes using the template & instructions how to mark the depth on the drill bit anybody should be able to install them properly without tearing the speaker up.