Casca -
I have an Etrac and my friend has a Deus... We both used to have AT Pros. They are both completely different machines. The Deus is super fast the Etrac is super slow. I also have an F75SE that is super fast. The Deus is very sensitive to small items and deep. The Etrac/CTX 3030 have the best VDI bar none. All other machines are really just beep and dig machines. Their VDI's are not accurate enough to know what you have really found unless you dig it up. And yes if you are hunting an old site you want to dig it all anyway. With the Etrac you can tell if its a nickel, or a wheat, zinc or copper penny because of the very accurate VDI 90% of the time. So if your doing a field use a Deus or Fisher or ? If your doing someone's nice yard you can truly cherry pick the best targets with accuracy and depth with an Etrac. Remember the Etrac is slow, so if you are trying to cover a lot of ground fast its not the best choice. I have used an AT PRO with all size coils and my F75 with different coils on a very old house site going in all directions. I took the Etrac and found 3 more wheat's I has missed. I have been digging since the late 70's and used many different machines. The Etrac is like a Cadillac....smooth a quality. Its like fishing, you cant just have 1 fishing pole. You need an ultra light pole for small fish and a large pole for salmon. It s the same for detecting. That's why I use an F75 deep and fast, an Etrac deep, slow, accurate VDI.
As for gridding and then going back over a spot again at a different time, I have noticed that like we all have, you always find something you missed and go, how did I miss that? I have found that when I grid, I do not always walk as perfectly straight lines as I think and I am missing some ground all together. Grid sometime in wet grass so that you can see your tracks and you will see what I mean.
As for the weight of the Etrac, it is heavy. I bought a detecting buddy online for less than $25.00 and can swing any detector all day with no weight issues at all.
Good luck with whatever you buy!
Its all about just having great fun an being out doors.
Gary from Oregon