Well, I had what we in the Southern segment of the US would call a "come to Jesus moment" in regards to my mic locker last night, courtesy of this subject (i.e. capsule swap in an NT1-A).
Warning, questionable and highly subjective observations ahead!
I swapped a spare capsule I had pulled from a Blue B8 bottle cap into the NT1-A I just picked up for $27 (shipped) on eBay. It seemed absurd and gratuitous, but otherwise the capsule was just sitting in a drawer so why not. Before the swap I recorded a standardized vocal test I do with all my mics. That test suffers the common problems of re-recording vocal performances on different microphones, performances differ and regardless of controlled distances, signal chain, etc... there will always be slight environmental differences. Of course I did the same after the swap.
So, on to my subjective observations. For the before and after, before it sounded more shrill and grainy by comparison. It is not bad with the stock capsule, but subjectively ranked would definitely fall below most of the mics and capsules I've tested.
The "after" is where my whole world started to crumble. Very hyperbolic I know, but here is what happened that was so shocking. It did not have a "sound" or character of it's own. There is no magic or mojo, nothing particularly special or unique about the sound. What it did do is instantly reveal every "flaw" in every other microphone and capsule I've tested.
Even the exact same Blue B8 capsule in my Blue Bottle, along with the same capsule on a custom Blue Mouse and custom Blueberry. All of them, by comparison, have sonic oddities, anomalies, fingerprints all their own. They all impart something on the sound that when compared to the NT1-A w/ B8 is instantly identifiable. I thought my ears deceived me when I did the comparison yesterday so came back with fresh ears today and had the exact same experience.
Outside of the Bottle none of the mics compared are particularly high-end (Sony C-100, Warm WA-47, custom Blue mics mentioned above with all caps, a 251 clone, UT Twin87, and several budget mics), but all the same I did not expect this combo to add anything interesting and it did. It set a benchmark for my mic testing project that reveals the sonic signature of all the other mics. It's unlikely to become a go to mic as it is often all those "flaws" that draw me to a given mic for a given source, but it will certainly have it's uses.
That's all, sorry for that highly subjective rant, I was just a bit astonished and wanted to share.