Being that you have the Simplex and now an Etrac, I think they will complement each other very well. With those two machines, where one lacks the other will cover.

Learn the etrac and also give the Simplex more time. It really is a nice machine and not afraid to tackle the trashier iron infested sites. The next thing Santa will need to bring you is that small 5" coil for the Simplex when NEL gets it out........that will/should make a really nice old site/ghost town detector out of the Simplex.

I honestly think this will make a better "combo" of machines than it would be getting the F75. I would rather have the Simplex ( with 5" coil) over the F75.

CoRe,Relic & Racers
MXT All Pro & M6
Big Red 440