As far as the EZ-Flash IV goes, if stuff is working fine, no point in updating.
Everything works just fine on 1.72 for me, so the only benefit to updating to latest version is... nothing, aside from the satisfaction of feeling like you are all updated. Doesn't make anything work any better or fix anything that wasn't working before, as far as I'm concerned.
They did fix a thing with using Chinese characters in file names, but... I doubt you used these anyway. And supposedly a glitch about writing 32MB games to NOR, but that's always worked fine for me.
Improved compatibility? Improved saver? How? Everything works fine already
I guess support for SDHC would be nice, but... I mean, with a 2GB you can already fit as many games as you would possibly want, and unless your EZ4 was one of the latter batches that came equipped with an SDHC-capable reader, it wouldn't really change anything. (Otherwise, people would have been able to update the original R4 cards to support SDHC, no? Or maybe stuff is different, idk.)
Either that, or every EZ4 came with SDHC-capable reader, just they never made use of it until now
They aren't gonna be releasing any new games with some kind of improved anti-piracy that doesn't work on EZ4, everything already works unless it requires special hardware in the cart, so
Really odd how EZ-Flash team handles this, though, considering they have multiple different hardware revisions of the EZ4, some of them only work well with the newer firmware update, while older ones don't really work with the new firmware update, and they don't even give any way of knowing if yours is an older or a newer one, no warnings at all, etc. kind of a let down.