Pinpointers Rock!
Seriously, it makes recovery time of a target much faster, so you can dig more targets. It also helps you from gouging or damaging a good find when you are digging around for it. I have used 4:
I started with a KellyCo Automax V4 which was free. It was a piece of junk. only gave at best 1/2 inch. Then it broke after 4 months.
As a stop-gap, I got a centech

from Harbor freight, it was cheap ($15), slightly better than the automax, but broke after 3 months.
Then I got a Sunray X-1 probe for my E trac. It worked great for a little over a year. The pros were it was on the detector, could be used like a little coil, so you could identify target easily by tone. It got a good 2 inches.
My Sunray began to crap out. It still works but there is a loose wire or something in it, so it falses all the time in midair even. This has reduced its effective depth and also makes it easy to dig after false sounds.
I got a Garrett pro pointer in March. I have had no problems with it. It works well. gets 2-3 inches. gives good indication of how close you are to the target. It is easily 'detuned' so you can get a closer area once you've found the target.
I suggest either Sunray or Garrett. It depends on what you want. I think all things equal, comparing my Garrett to my sunray when my sunray was fully functional, I like the garrett slightly better. It seems like it is much easier to find the target with it. It seems more durable. Besides having the traditional pointing at the end of the probe, it has a sensitive strip along the side, which makes it easy to run across a pile of dirt quickly to locate the target.