I really hated my Garrett GTI2500, my advice is to get rid of it. I have a X-Terra 70, Musketeer Advantage, and GP3000 now and now I am thinking about buying an E-Trac also like you.
I want one and yes the E-Trac IS the best coin machine on the market BUT as with ALL FBS and BBS machines you must know they are slow working machines to achieve the maximum depth and readings. They are not rapid speed hunters with no loss of depth like the Musketeer Advantage.
In heavy trash, in house yards, parks, schools, boulevards, churches, etc. the E-Trac is ACE, THE best machine on the market and cannot be beat BUT in very large relic fields, huge farmers fields, very big homestead yards, etc. (with low amounts of non-ferrous trash) with massive amounts of ground needed to be to covered in a day for speed hunting I would NOT use an E-Trac, as a top single frequency VLF(X-70, Musky, Vaquero, Tejon, F75, XLT, or MXT) is about 3 or more times faster--more ground coverage in a day.
Also in black dirt plowed farmers fields for the FBS and BBS machines, the depth advantage over a the very top single frequency VLF's(like the Musky or Tejon) is not there(don't shine on air tests). They shine as having the very best depth and the best ID discrimination in some mineralization, wet saltwater beach, and tough ground as THE best and I want an E-Trac for the spring!