I had the 800 and the E-Trac. I still have my E-Trac.
It's not that the 800 didn't meet my expectations, because I still feel it's right there with the E-Trac/CTX, I will own another in the future I'm sure, but I needed some quick cash and the 800 was it.
Depth wise I put the 800 head-to-head with the E-Trac at a site where I know for a fact there are many deep coins. I have cleaned this area out to the limits of the E-Trac/CTX. I took the 800 there on many trips and found nothing missed by the E-Trac or CTX. For this reason I feel the 800 depth is about the same as the E-Trac/CTX. Now in high trash and for low conductors the 800 is far above the E-Trac/CTX.
Stability is important to me as I just hate a noisy detector. That is why I've never been a Fisher guy. Sorry Fisher guys, the detector is a killer, but too noisy for me. The Deus and the 800 are a good comparison. I found the 800 a little on the noisy side, unless you turn it down, but it was tolerable.