I think that the most important thing to look at when you debate whether to buy these CM4s or not is mostly specs. They're very linear mics and they're not flattering at all, in fact they might sound a bit dull or boring, but that's what EQ and processing is for. They're moderately low noise (not the lowest, but workable) and they're moderately sensitive (not the most sensitive, but not weak either) so they will take some EQ all right if you don't overdo it (and if you have good, clean preamps). They have smooth pickup patterns (a slightly large cardioid pattern) and no obvious peaks and dips, and they can take decent SPLs (so they're fine on overheads, maybe even hihat, I wouldn't put them under a snare though or in front of an amp). And compared to most of the microphones I've heard in their price range, they're not harsh or brittle so they don't need that much processing to sound OK. The Schoeps mics might take higher SPLs, be a bit more consistent or have more flattering frequency response but they cost five-six times as much, so I think that if you already have a pair of those mics you really don't need the CM4s except for backup mics or for utility purposes, but really, these days, €250 takes you a really long distance.