well guys, I've been flying for a long time and I have been changing my tx crystals for at least 10 or more years. I have never had a problem. For the last several years I have had a JR 9303 that has a module in it which I changed the crystal in when I got it and it has never given me any problems. As for switching to 2.4, that really isn't an option for me as I have way to many 72 mhz planes to switch. My favorite of which is a 33% yak 54 with a 3W 80 on it.