This is more of "in the water" sub forum. So I only know underwater machines. I pwn a fisher 1280, bhid [not the 300] and an excal II.
Narrow down what you want to hunt. Land or water. And go from there. Mostly land, I cant help. Others will. Water. All three of the above machines have found me stuff. The 1280 has an affinity for silver for some reason. My primary machine is the excal II. I love it. And the backup id machin is the beach hunter.
If I were to buy a new machine. I would go with another excal. Thats just me. My second pick, would be the cz21. Thats fishers saltwater machine.
Take your time with before you pick. Don't forget about the other manufacturers. Like Tesoro. They have good machines with good warranties.
Hope this helps. HH an GL. -Joe