Harold,
Here are a few notes on these machines.
The Garrett is a great machine for Coin Shooting. The bell tone does work very nicely, but this is not a relic machine. I have owned one and the depth is just not that impressive. Now on a coin up to 6".....this one is deadly. But to dig bullets, buttons, items other than just coins......not my first choice.
The Whites V3 is a different type of machine. I have not owned one, but I am hearing good things. This machine has a wider range of ability. It will come with a higher learning curve, but once mastered you would probably be more happy this this one.
You should consider what type of hunting you plan on doing. Todays detectors are really aimed at certain applications. Coin Shooting (Garrett) Water (Mine Lab) - Relics (Whites, Fisher) etc etc.
Considering that in either case, you are going to be spending a fairly large amount of money, consider what we plan on doing with this machine.
I have actually become quite attached to the Fisher F75. I find this to have superior depth on coins, relics, etc., but it does seems to have a bit of trouble properly ID'ing in mineralized soil.
If you have some specific questions, just post them here. The folks on this forum would be more than happy to assist.
Good Luck! RickB(SC)
RickB(SC)