Main practical difference is a better (autofocus) camera in the E72, but the E5 is ok for anything but closeups. extended-DOF camera means anything from about 60cm to infinity is in focus, works better than you'd think, but not up there with the carl zeiss autofocus nokias (but then nothing is cameraphone wise really, though some get close).
S60 3rd edition is getting dated, but it's very refined, It all "just works" but finding menu options etc. can be tricky if you're not used to the mindset. Having said that, I've given the E5 to my GF, who'd got an itouch but never had a smartphone. She's been happing sportstracking, using ovi maps, last.fm, facebook etc. without any trouble.
Battery life is great, as is the size and build quality. Slips into a top pocket and will get a full day constantly connected & online tweeting and the like. Feels solid like I could hammer nails with it...
Keyboard is great - I prefer fold out qwerty in general, but this is good. (preferable to touchscreen IMO). Call quality etc - it's a nokia, it's perfect.
Volume keys are awkward/stiff. They dropped the ball there a bit. Music player aint flashy, but does work well enough. Screen is ok but not great outdoors.
Most of these comments apply to an E72 too, very similar.
In summary - if you want a phone that's a phone first, text and email second then all the rest, probably a good choice.
5800 is LCD, not OLED. N85, N86 is OLED.