I don't wish to be unkind to those who use other brands. I personally like all of them. But, I will say this, the Tesoro and Laser (same company) are easy to learn and very excellent.
I use the Tesoro DeLeon which is the US equivalent of the UK Laser Hawkeye. I could never express here how much I like this machine! If you can, just borrow a Hawkeye and spend about 10 hours learning it. Take it to an old site (that has trash) where the coins and relics are known to be in the 5 to 8 inch depth range and you'll kill with this machine.
It's NOT that the Tesoro product is so much DEEPER than other brands. The thing about the Tesoro/Laser brand is the target separation ability and sound. Tesoros have about the smoothest and easiest to read sound in the business. Even a child could learn the deep silver coin sound in a few hours. With Tesoro, it's super easy to dig good coins out of the iron trash.
My last old coins (1800's) were dug right beside or under big iron trash.
If you're hunting plowed fields than get the Tejon or the Fisher CZ 3D. The Fisher is the deepest practical VLF made today but it doesn't work well in high trash areas. This same thing holds for the Tejon.
Fisher CZ 3D can detect a buried dime (18mm) coin at 13 inches (no joke).
I'd recommend NOT one machine but two. I'd get the Hawkeye, Cortes, or DeLeon for hunting lots and yards, etc. I'd get the Tejon or 3D for those super deep low-trash areas.
http://www.garysdetecting.co.uk/
Best to you!
Badger