The practicality is that you always have a key, and you know where it is. Iron Cobras come with a key and allen tool, and I cant tell you how many times that key has bailed me out. I try to bring one with me to every gig, and I have several in the glove box of my truck, but on many occasions I have gotten on stage to set up and realized I didn't have a key on me, so I had to use the one on my pedals. So having one on the snare would be just as useful.
just arrived at this site in the process of searching for another one of these key holders.
i have installed these in a number of drums and like them because i think it's a convenient way to store a key. plus i love Gretsch's streamlined styling, the way the key handle matches the bass drum T-rods, etc.. i have had some trouble with them installing or holding properly but always managed to correct the problem. i always laugh when drummers talk about things like different cymbal sounds and the possibility of things rattling and then proceed to bash the shit out of every piece of their equipment. i think the hip trend today is to have no internal muffling either and to place special gummy things on the head and then store them in their own cute little box, saying mufflers also cause unwanted noise. i have also installed Gretsch tone controls (i have always loved those huge round knobs too) on different drums. i don't usually play loud and i haven't noticed extraneous sounds from either the key holders or tone controls.