The basic F75 came out first, a little while later the F70 that was programmed a bit differently but had something new called SL speed, boost, which was tweaked some then added to newer model F75's I assume that were renamed the SE's.
There seemed to be a few more versions of F75's over the years, SE, LTD, but pretty similar models with what might be a few more programs and/or settings but the basic abilities they all possess seemed to be about the same.
If you learn them they were all deep and productive.
The newest incantations have DST, a publicized and pretty popular new feature to quiet them all down, but I suspect there have been many other behind the scenes tweaks and upgrades to the programming along the way none of which were ever talked about or even mentioned.
The engineers at FTP don't seem like the types to sit on their laurels or ever be truly satisfied with their success.
I hunt with an F70, primitive by flagship levels and missing many features the F75's have but also with those same natural abilities as the flagship IMO.
I can get shockingly deep, I can find targets in extremely difficult sites like heavy trash and iron, I might not have all those extra features or DST that could possibly make things a bit easier but there are always workarounds that can achieve the same things with a little work and knowledge.
Even Dave J. has stated that nobody that uses an F70 should regret using it over any of those flagship models and I believe the same should be thought of using one revision or model over the other regarding most of the F75's.
The basics and innate natural abilities are there on all of them, picking between them is like trying to decide between different colors or features on Cadillac's....at their core they are all still Caddy's.
Pick one with the specific features you want and go for it, learn it well and the rewards will be plenty.
