Thanks so much for all your reaponses! I'm still undecided... My thumb is usually the same through all night, no swells or shrinks for me, so, is there any other advantage of having the interchangeable system? Because usually when you drill a thumb hole it has to has the same feeling from one ball to another, isn't it? And i have other concern, the price. How much is the difference between a regular drill and the one with the interchangeable ones? And one final concern... I have a guy who has been drilling my stuff since I started, great guy, he is my friend now, but he doesn't have the tools/kit to put the interchangeable system to my balls, there is another pro shop who can make it, but I'm afraid that once my friend finds out he is gonna be offended or something, do you know what I mean? Also my friend gives me a good discount every time I go with him... Is it worth all the hassle to get the interchangeable system? I have three new balls (arctic sniper, sigma sting and tribal fire) and I don't want to drill them until I'm 100% sure.
Thanks!