This question comes up a lot, but rarely gets a good answer -- the reason is simple: nobody (or practically nobody) has both mics. I'm sure that'll change as time goes on.
I've got two older 414s that I got used, and they're great

- in the absence of first hand information, your best bet may be to think about the mic techniques that are available to you with multi-pattern mics versus cardioid-only. I do use one or both of the 414s in omni from time to time, and plan to explore mid-side, one of these days.
edit: while we're on the subject, let me convey a cautionary tale from the novice (me) -- the 414s, and probably the 214s, require a full supply of 48v phantom power. I recorded a band at their rehearsal a couple of weeks ago, and had very little time to set up -- I forgot about the requirement, and ran both overheads off my firewire interface with only the built in phantom power -- the voltage was insufficient, and the tracks were not as good as I'm sure they would have been (and I had a dedicated 2 channel phantom supply sitting in my bag the whole time -- doh!!!

) - the point here is that if you're like me, and often use bus powered interfaces for mic pres, you might also want to budget for a dedicated supply (and then remember to use it)