Let me throw in some clarity here.
The deepest detector is dependent on the skill of the user, period.
It's kinda like when I purchased my E-Trac. I'm a sound guy, not a VDI guy. So when I was looking to pick up a new detector I wanted a quality sound machine. I settled on the E-Trac, and was totally blown away by sounds, and scrambled using all kinds of modes & patterns, got frustrated because I overwhelmed myself. I quit using the E-Trac for a while and went back to my trusty Fisher 1260X. Then I settled back down, stripped my E-Trac patterns & modes back to factory and went back to the basics. I stopped looking at the screen until I was ready to dig based on sound alone. After just a little bit then, I got very productive with quick recovery, only dig trash occasionally for verification, and on my last hunt, dug 32 coins in just a couple hours, with quite a number at about 10". It would have absolutely hit deeper had there been deeper coins there. The Pro-Pointer was darned handy in the sand and turbo boosted productivity. Grab a target and on to the next.
On a simple, quick hunt, I pull out the 1260X. But when I'm going for a serious hunt, I now pull out the CTX (since I'd fried the E-Trac at the time) and settle into "listening". Took a while to get used to the sounds (E-Trac & CTX are the same at the very basics).
Even as an experienced sound guy, the Minelab learning curve was more than any machine I'd ever used - pretty frustrating as I'd expected better out of myself.
I'll sum this up in saying that depth is almost exclusively dependent on the skill of the user, regardless of the machine used. Any quality machine from any manufacturer today can hit pretty deeply. Learn to love any machine you have, or you'll spend more money on equipment than the value of the finds you dig! But then, if us addicts are an example - the prospect of wealth is only a light entertainment dream when it comes to our investment in equipment.
Everybody gets lucky sometimes otherwise. But productivity makes you smile
