Hi mick, welcome aboard. I have had my 4500 since its release day. I have found more gold with it and i have had many of minelab,s gold detectors. Its a back up now and the zed is catching it fast in terms of gold recovered. My advice is to read the manual cover to cover a couple times with the detector in front of you.
If you search the forums you will find lots of info on settings for different situations.
Try get out with someone who has used a 4500 heaps.
Probably best advice is to swing slow and get very proficient at recovering targets and moving on.....so you can maximise ground coverage during a detecting session.
Good luck, stick with it and you will get some nice deep element 79.
Cheers RDD