Is the Excalibur deeper, in the hands of skilled almetal hunter I would say very close, but if you run up against a DF Pro hunter...like (Cfmct-PI)
Then I would say it would be Very site dependent. Each have there own place in the field like the Infinium w/10x14 mono which is deeper then both, but it can be, a love hate relationship with the infinium. I have dug a few honkers (19gr) in the 17 inch range, amazingly with the excalibur 800, most rings I find are smaller and hit between shallow and 12 inchs. Having a deep detector is great, but it always seems the good stuff is a foot deeper.
Did a little learning about each of my detectors a month ago on freshly buried rings, found out later the ladies ring cracked during the pull from 14 inchs, results could be different at your beach..and all the detectors were run on Hot settings, like I run on this beach all the time, basically a tune up before hunting season starts here in OC this summer.
And, I am still considered a rookie with the DF
The Df did average on both, 10 in (man) and 4 inchs (womens)
Size 13 Mans 14k, 7.5 grams ............16 inch's........none.......................14 inchs.... Garrett Infinium PI, Doc's Amped excal..........rest came in between 10 & 12 inch's
Size 6 1.5 gram 10k women's ring......14 inch's....... none.........................6 inch's......Garrett Sea Hunter PI, rest of the pack started hitting at 4 inch's
So the Ls has the depth on the larger rings (10x14), the SeaHunter does better on the smaller ladies ring, small (8 inch) coil hit mans ring at 10 inchs