which would be better to upgrade to, Minelab e-trac or Tesoro Cortes ?

I have been using a Garrett Ace 250 for about 4 years now, last year I bought a 15 x 13 SEF butterfly search coil for it and had a lot of success. Recently I have had a couple of great opportunities to hunt at some rather old/historical sites. One problem though..................interference from powerlines and such. It's very frustrating so I have decided I want to upgrade. I have been doing alot of reading and research on both the Minelab E-Trac and the Tesoro Cortes. Which is better ? The Cortez is only about 1/3 of the price of the E-trac and it also comes with a lifetime warranty but does that make it a better detector ? I like detecting for coins and also for relics. I'm in upstate NY and don't ever hunt beaches. Which do you reccomend and why ? Thanks for any input !

While I like both Minelabs and Tesoro's a move from an Ace to a Minelab would be a large learning curve but not impossible to over come.  The e-Trac's display can get confusing to the new user.  I have used both and much prefer the Cortez just because it is easy as heck to use, light weight, extra long battery life, and many coils for it including the Clean Sweep Coil.

Both these are excellent machines and just depend on how you like your toast buttered.

http://www.tesoro.com/product/detectors/cortes/

I saw my first Ace250 Friday in a field where some guys were hunting for civil war relics.  My first feeling was that it looked like a toy.  I know a lot of people use them, but no one would use one who has used a really good machine.  I would consider anything as an upgrade from an ACE250.  I have had over 30 machines since 1970 and right now am using a Tesoro Tejon for relic hunting and it is darned deep.  I know for a fact that it is deeper than a DFX on a minnie, in fact there were two DFX's and neither could pick up the minnie which the Tesoro Tejon easily found.  Many of the newer machines are very complicated.  They have many options, but the learning curve is steep.  I need a tid machine myself because I quickly got rid of my DFX which was baffling.  I am considering the Cortes because Tesoro are great machines and they do stand behind their warranty.  They will fix that machine with no questions asked, no matter what.

One machine that seems to be over looked is the Sov. very deep. 

 I hunt under a lot of power line right of ways that go through neighborhood batlefields (cw). I bought a tesoro. It a conquistador they do not make it anymore but it has a frequency shift on it.
 The thing runs deep and I never get interference from anything. I like Tesoro. Less stuff to go wrong and warranty forever. It will find anything. Its just not going to say v nickel in a little display is all .
Good luck
TnMtns