I have an Infinium and I think it is one of the best PI units out there for beach hunting. But I did not buy the Infinium as my first PI. I had several years under my belt using PI units before I got an Infinium.
You have to be aware that the Infinium was designed as a gold prospecting unit first. Because of that, it has features that some of the other standard, simple beach hunting PI units ( ie, Sea Hunter, Whites PI's, Detector Pro, Tesoro Sand Shark) do not have. One is the ability to ground balance ( ie, set up the unit for the soil/sand conditions). Another is the ability to go through a frequency check to find the best frequency to run in that area....this mitigates any EMI problems that may occur. None of the other PI units to my knowledge, have this ability.
One more is that the threshold and discrimination ( pulse delay ) features work in conjunction with each other to set up the unit to be stable. Hunting a salt water beach with an Infinium takes some work. You have to set it up correctly, and also have to know the subtle nuances of how a PI unit runs. The latter comes only with using PI units for a while. You can't run an Infinium at optimal settings day one....it will drive you crazy.
If you do decide to get an Infinium, one of the most unique features as mentioned, is the hi/lo and lo/hi signals it gives on targets. These signals, when repeatable, allow a hunter to make a better educated guess as to not only what the target may be, but is it an actual target or a false signal. REPEATABLE hi/lo and lo/hi signals are almost always some type of metal. There is no mistaking them vs. a false signal. Be aware however, that iron can signal as either a hi/lo or lo/hi. Iron is STILL a PI's worst enemy.
One thing you should also be aware of when using the Infinium in knee deep ocean water ( or any salt water environment where there is current or waves running over the coil from 6 inches to 2 feet, is that you MAY get a threshold change when the waves run over the coil when running close to optimal settings ( that is, settings that are the most sensitive to gold...as well as salt water conductivity). If the coil is deeper, where the waves and currents do not affect it as much, the threshold changes are less.
In my opinion, the advantages the Infinium has over other PI units is well worth the price. The thing is, it is not an entry level PI and without some basic PI experience, it may not be a good first choice.
