For live stereo recording without "spot" microphones, small-diaphragm condenser microphones are the only type that I would ever want to use. At any relatively normal recording distances in any relatively normal recording venue, a surprising amount of the sound reaching the microphones is reflected sound arriving off-axis, so the off-axis response is far more important than it would be (for example) when spot-miking a vocal soloist in an acoustically isolated studio environment. And physics dictates that the larger the microphone, the less good its off-axis response will be.
Experience also tells me that no one directional pattern is always best. I can't fathom the idea that a person is supposed to be a partisan of one particular recording technique, independent of the actual acoustical situation that one is recording in or the type of music or the arrangement of the performers in the space; there's too much variation in all of the above for any one recording technique to be preferable all the time. So my options are (a) many pairs of separate microphones (at least one pair for each pattern), (b) a pair of switchable-pattern microphones, or (c) a pair of microphones that can accept interchangeable capsules with different directional patterns.
Of these three I prefer (c) over (a) for economic reasons, as well as feeling like it would be stupid to own 20+ complete microphones when owning just one or two pairs (with however many interchangeable capsules) will do equally well. And I prefer (c) over (b) because the only switchable-pattern microphones with a full range of patterns (at least omni, wide cardioid, cardioid, supercardioid and figure-8) are dual-diaphragm, which means that their patterns on the omni-to-cardioid side of the ledger won't be nearly as consistent across the frequency range as what is available from single-diaphragm microphones or capsules (i.e. the off-axis response issue again).
So I've been a real fan of high-quality, single-diaphragm, modular condenser microphones (i.e. those with a sonically neutral amplifier and a range of interchangeable capsules), which I've used since the early 1970s. I started with the AKG C 451 E series (CK 1 and CK 2 capsules), then Neumann KM 83s and 84s, and then found the Schoeps CMT 30/40/50 series, which was soon superseded by the Colette series, which they still make.
I suppose if I absolutely had to give up all but one type of microphone that I own, I would keep my pair of Schoeps three-pattern (omnidirectional, cardioid, figure-8) microphones that I bought in 1973. But then I would severely miss using wide cardioid, "open cardioid" or supercardioid microphones in situations where I feel those patterns are called for. And sometimes an "axially" addressed omni or cardioid is preferable to a "radially" addressed microphone (though the reverse can be true as well). So I hope that it never comes to that kind of decision in reality.
--best regards