For what it's worth, here's my comparison of the two pinpointers I have:
I have a Treasure Mate and for the most part I like it. It has Tesoro's lifetime warranty which is a HUGE plus when it comes to a pinpointer. I've had it about five months and had to send it in for repair a couple months ago. They replaced the ground balance and tuning pots and recalibrated the unit. To Tesoro's credit, it came back working even better than it did when it was new.
It has some things I really don't like:
1. You have to remove the four screws and take off the bottom cover like you do to change the batteries to change the mode from vibrate to audio and vice versa. Also you cannot put it in both modes at the same time, you have to pick one or the other.
2. The 9V battery fits really tightly and is a pain to change.
3. The two knobs for tuning and ground balancing turn really easily and do so just about every time you put the pinpointer away after using it until you put O-rings on them to keep them from moving so easily.
4. The on/off switch is a rocker type knob which I have accidentally turned off (and on) a few times.
I just got a Garrett Pro-Pointer. I've only hade a chance to use it a couple times, but from my limited time with it I definitely like it better than the Treasure Mate. The only negative from my perspective is that you can't turn the audio off, it always vibrates and beeps.
The Pro Pointer gives a little more depth than the Treasure Mate and it detects up the sides too whereas the Mate is mostly in the tip.
The Pro-Pointer is basically turn on and go which I like better but I guess in some applications like gold prospecting it wouldn't be as effective without the ground balancing. Battery replacement is apparently very simple: just unscrew the bottom and drop in a new battery.
The Pro-Pointer seems very sturdy and solid, but it does only have a two year warranty vs. the lifetime for the Treasure Mate.
Garrett dealers are selling the Pro-Pointer for $127 and change with free shipping and extras including a pouch, brass probe and a couple of Charles Garrett's little books. If I recall the Treasure Mate with free shipping was $160 something by itself.
To sum it up, I'd give the Pro-Pointer the edge in how well it works, in cost and in user-friendliness. I'd give the Treasure Mate the edge as far as the warranty.