I have 2 detectors, the first one was a Tesoro Laser many years ago. Its Ok, lightweight, fairly ok discrimination, but doesnt do well on ares with a high amount of slag. Being near a railway town some of the fields are covered in the stuff. The second I bought a few years ago, primarily because I was helping out with a detector survey of a roman marching station and I needed something better. That was a Minelab Explorer, I think version 2 is out now. Its not a cheap bit of kit, but I did get it as part of a deal with a bundle of kit which included 3 different search heads. It had the standard fitted 8"head, a deep seeking 12" head and a smaller 5" head. I almost always use the larger head for fields and the range goes down to approx 12" depending on the object. The small head is specifically for beaches, shallow water etc, I havent had chance to use that yet. Its got a digital display and a booklet the size of a bible. But speaking to our main man who helps us with detecting he just said to forget the book, turn sensitivity up a couple of notches and the discrim down a couple of notches. Bingo. The display also gives you an idea of the ferrous content, what the object is likely to be, ring pull, ring etc. It also gives you a depth for the object as well. As I said not a cheap bit of kit, but I wouldnt use anything else.
For the record one day alone out of one field we had 360 Roman coins, a handful of brooches and a gold Celtic stater.