I've told this story before to many people...I'll try to make it short as possible, but it won't be.
FACTS:
I hunt with 2 older guys...I'm 33 now (born 1980), these guys are in their 60's. These guys have been detecting since the late 70's and have much more experience than I do when it comes to detecting. They have 30+ years experience each. This is my 11th year detecting. Just setting the back drop that none of us are rookies.
When I met these guys back in 2004, I was a rookie using a Garrett GTI 1500.
Rick was using a White's DFX at the time. Jim was using the First model Explorer.
They pretty much outperformed me everywhere we went from 2004-2007, but I WAS guessing a lot had to do with experience. We hunted a lot of fairgrounds with high amounts of trash where you really didn't even detect targets past 5-6 deep. I mean...those were deep finds for those places. But since most finds were 4" or less we all made decent finds. They were just faster at locating their targets than I was as they had more experience.
However, Jim was getting better with his detector and when we hunted he was making deeper finds on average than us.
Anyway, in 2007, we found an old fairgrounds that didn't have nearly the amount of trash as the others we had detected.
It seemed most of the targets were either shallow (3" or less) or deeper.
First day we were there, Rick (DFX) and myself (GTI 1500) were convinced after digging 1 silver coin, a wheat penny, and few clad coins that this place stunk. All the good coins were gone.
Jim (Explorer) strolls over and shows us 30+ wheats and 8-10 silver coins. Tells us all the coins were 6" or deeper, some as much as 9-10" deep.
Jim would get these deep signals...point them out. DFX and Garrett would swing over them...not even make a sound. Complete silence. He'd swing the Explorer over it and it would scream.
This didn't just happen once. This was every Wednesday all summer long...same place...8 hours detecting...Jim kicking our butt.
The Garrett and the DFX had settings changed too...no coins being found over 5-6" deep there by us. Jim was averaging 6-8 silvers every week and probably 30+ wheats with an Explorer 1.
That fairground is where we all learned the capability of finding deep coins with an Explorer.
TRUE STORY:
End of summer, Rick buys and Explorer II. Rick gets Jim's settings, but programs it to the equivalency as Exp I and Exp II are a little different. Jim walks out...locates deep whispers (as he calls them)...calls Rick over. Rick swings Explorer II over the ground...ahh...what do ya know

Rick's Explorer II makes the same sounds.
Rick goes detects all day there...his 1st day using the detector and rips it up. Finds 6-8 silver coins, buffalo nickel, indianhead, 30 wheat pennies.
The next spring I bought a Minelab SE.
My first week with a Minelab SE I dug a Mercury Dime at 8" deep with 2 nails in the hole. My GTI 1500 would never have found that coin. I dug over 5,000 coins with my Garrett and only 1 was over 6" deep.
IMHO, A Garrett GTI 1500 feels like a cheap detector. It has a lot of good qualities. It has target imaging and exceptional pinpointing, especially when compared to a Minelab Explorer. And its pretty light weight. I'm not bagging on a Garrett GTI.
However, in 4-5 years using it...I saw nothing that made me believe it was capable of CONSISTENTLY detecting coins at ranges beyond 6." Minelab Explorers will do this.
So when someone says that a cheap detector will find the same things as expensive detectors...I find that EXTREMELY short sighted.
They might make the same kinds of finds, but if you digging at places where good coins are 7+ inches deep. There is no way that cheap $300 detectors are going to find coins consistently at those depths.
Sure, if targets are shallow...then every detector has a great chance of making good finds.
But if you are talking deep, small targets, no way to convince me Minelabs aren't worth the extra money.