The SE and the F75 are both top notch machines. The SE is better built and give's you more information. I can almost always tell a pulltab from a nickel with the SE using the digital screen. It is unrivalled for TID. I may be a bit biased because I have yet to learn the SE, it has a longer learning curve, IMO. So, right now the F75 is more fun for me.. BUT... beware the F75 will drive you nuts at first because it is very noisy. Some machines like a Tesoro or a Sovereign are quiet until you come across a target... the F75 is a constant blast of chatter from minerals and small bits of iron or whatever. The tones on the F75 are brash and harsh compared to the "fluty" tones of the Explorer. The F75 is the most ergonomic detector I have ever used. The F75 probably has an edge in high mineral and lots of iron. I think the Explorer probably has an edge everywhere else. Both work well on the beach in the dry sand but the Explorer works better in the wet sand and the F75 gets jumpy and goes nuts if you stick the coil into salt water.
Another option for you to consider is a used T2, which is very similar to the F75, the main thing the F75 has over the T2 is that the TID will work in All-metal on the F75, not on the T2. The F75 has a little more depth, or so they say. The T2 has a wider range of numbers in the lower "iron" area and the F75 has a wider range in the higher numbers. You could also look for a used F75 and save a bit of money. Then buy a used Explorer too. The only difference that I can see between the new SE Pro and the SE is the new coil and a decal.
FWIW, I really like both my Tesoro Cortes, (for coin shooting) it read's almost all coins at "95" on the meter, and my Tesoro Tejon with a 5.5" coil for relic hunting. I use a 5.5" coil on both of the Tesoros, you really lose very little depth and gain much seperation. In fact I don't know anyone who uses a large coil on a Tesoro. A lot of relic hunters around here use the Tejon.
So, I would buy a used F75 and send it to Fisher for the "waterproof" upgrade, ask them to calibrate it while they have it. Buy a used SE, be patient, save money... get both!
I would not sell my SE of my F75.. or for that matter my T2, or my Cortes or my Tejon... I might sell my SovereignGT.. They all have their use at different places and for hunting different things.
If I had to venture a guess I would guess that the SE might, under some conditions, find something that all the others miss but you are going to have to spend some, (a lot actually), of time with it.
The batteries, (4 "AA"), last about 40 hours in the F75 but the SE comes with a rechargable battery and a "AA" battery pak.
Hope this helps... you're probably more confused than ever now... laff.
More info on the F75 here:
http://www.dankowskidetectors.com/discussions/list.php?2
http://www.fisherf75.com/
Explorer here:
http://www.treasuregizmo.com/settings.htm
http://usetheminelabexplorerlikeapro.blogspot.com/2004_11_11_archive.html
http://groups.msn.com/MinelabExplorerXSusers/_whatsnew.msnw
http://66.51.97.78/coinist/mtipspage1.html
http://forums.detectorbase.com/forumdisplay.php?f=18
http://64.150.165.38/ubbthreads/ubbthreads.php?ubb=cfrm
Tesoro here:
http://64.150.165.38/ubbthreads/ubbthreads.php?ubb=cfrm
And the best here of course:
http://www.findmall.com/
Julien