It was meant to be funny, but it's not a joke.
My first reaction was: wow, this thing has dynamic driver-like bass! Which it truly does in no way other BA I heard has.
However, it is boosted - equalizable though. Very high quality. But RE-400 has even more extended bass without a boost in the recently derived configuration. No need for an equalizer at all.
Shelved treble was always there (can be equalized), light texture - but while RE-400 treble is a small bit thicker, it is nowhere near as shelved by default and can actually be made fully neutral with a trivial mod and right tips.
Total highs extension is on par.
Mids are indeed very nice in SE-5. But RE-400 mids are just as nice.
Now the upsides: very low distortion everywhere. However, RE-400 also has very low distortion everywhere.
Nice comfort - but RE-400 are more portable and lighter in ear - and these RE-272 long tips are fitting very well.
Cable - that one I don't know yet.
The big upside of SE-5 is isolation. It's a lot, twice as much as RE-400, which don't have too much.
Soundstage - RE-400 wins, SE-5 has something off there even when equalized, it is rectangular and splits instruments weirdly at times - they sound like they're mixed in post-production instead of being recorded together.
RE-400 has reverberation in highs, SE-5 doesn't - that's a matter of taste, but I find this kind of reverb very natural, room-like.
Ringing - SE-5 rings slightly in a few places like most BA-based IEMs. Not really distracting, but there, audible mostly when equalized as its in the high mids and highs - results in an "oversharp" feel to the sound. RE-400 doesn't ring.
So to speak, Hifiman RE-400 with some slight tuning (tip rolling and removal of the damper in my case) is one of the best or perhaps the best IEM out there.
Note: I haven't heard all or even most of CIEMs - however few are dynamic driver based or even hybrids. The main unfixable problem (can be reduced but does not go away) with BAs is the relatively narrow bandwidth and ringing. And because the bandwidth is narrow, you need more and then need crossover networks that mess with the phase.
Perhaps I should try FutureSonics Ear Monitors some day...
Edited by AstralStorm - 2/23/13 at 12:07pm