Tysin.
You will feel like you have just stepped out of the dark ages if you upgrade to the X-Terra 30. my first detector was a Tracker 4. I had it for a couple of years. I sold it and 6 weeks later, bought the X-Terra 30. The difference just blew me away. you have a much better idea what is under the coil. having visual information plus the VCO pinpoint both really help to sort out your targets, neither of which are on the Tracker. you will still dig rubbish, but a lot less. You will have a fairly good idea when you have a gold coin under the coil a opposed to a screw cap.The numbers go up by 4's. A $2 coin will generally bounce between 28 and 32. They can lock in 32 and on the odd occasion, 28. Also, they sound noticeably quieter than a screw cap when you listen to the pinpoint tone. A $1 coin will sound louder than the $2 coin and a bit quieter than a screw cap.
Also, you will notice that pull tabs will bounce around on the visual information than say a 10c piece. Both these targets can bounce between 12 and 16, but pull tabs tend to be less stable.It's a rare detector that can separate them.
The beauty about having a visual discriminator, is that when you get a solid sounding signal, if the numbers bounce around all over the place, you know it's junk. The Tracker 4 can't do this.
I don't hunt around play equipment that often and it's been a few years since I owned the Tracker, so I can't give you a strait answer on which is better around the equipment.
The X-Terra really excels in iron infested ground. I've hunted the burnt out ruins of a couple of places with both these machines. I had to turn the Tracker 4 off as it was simply overwhelmed. I hunted in the burnt down ruins of an old miners cottage, with the X-Terra. The ground was utterly infested with nails and other significant metal debris, yet though all this, I was still able to get clear signals. I pulled up my favorite relic on this spot; a gun powder flask.
Just a few things to think on from a fellow Aussie.
Mick Evans.