I've used GBs, the old Greenlees, the newer Greenlees with the on/off switch attached to the cap, and the Ideals. Also the old Fluke w/o the audible, and now the newest ones w/ the push button. I like the newer Flukes the best--it has an auto shut-off function and the option to have audible or not. The flashing signal to indicate it's working is great too. And it's not constantly beeping in your pocket when you're not using it.