Ektapan has been my dad's standard 4x5 film for, I dunno, 25 or 30 years. He switched from Plus-X and has never looked back. His somewhat non-technical reason is that Ektapan has "far more zip" than Plus-X.(posted 8489 days ago)What he basically means is punchier contrast and a somewhat different spectral response. Most of his work is tabletop product shots lit with a couple of big banks of (WWII surplus!) florescent lights, sometimes with some hot lights mixed in. With Plus-X, these lighting scheme can yield somewhat blah results, given Plus-X's tend towards low-to-medium contrast and a somewhat grayish look. With Ektapan, this stuff just "pops".
A friend of his - a portrait and wedding specialist who mostly uses studio flash for portraits - also made the switch years ago for his 4x5 work. In his case, it was from T-Max 100 to Ektapan. He finds it a far easier to handle film, and loves the results.
Because it's only a sheet film emulsion, Ektapan is not very well known - but many folks who use it swear by it. Let's just hope that Kodak doesn't phase it out soon (after all, it can't be a very big seller!)...