I do a lot of sound capture myself and was looking at the Avantone CK-40, but it may be cumbersome for your uses.
I saw the CK-40 and it looked good, but it's definitely too big for my purposes.
The AT4050ST is well recommended here by one user and it seems the limited range stated by AT is not a problem. The mic will capture plenty of high freq information.
This is the only AT model I found a serious contender. I'm interested in doing MS and I could have my cake and eat it too with this one. It's strange though that with XY at 90 degrees the S/N falls to 69 dB. In MS it's above 77 dB (?).
But I don't know what's going on with AT's current lineup of stereo mics: if you check the Fq response charts, they're pretty flat to about 5k and then there's major Fq response spikes on every one of them. With the 4050, combined with a steep roll-off starting around 14k, you've looking at 15 dB's of variation from 10k to 20k. Even the lowly 822 looks better. Weird.
I read some negative comments about the Rode, but I can't remember where or what was said. Just left me with a bad feeling about it.
Yeah, I remember reading some negative comments about the NT4 too. I'm wondering about other things like wind sensitivity and handling noise, and how delicate it is.
If you really like the AT822, why don't you buy another one? They are not hard to find used either here in the Yard Sale or on eBay. Or, get an AT825 if you want a balanced output; they are pretty easy to find too.
Good question: I found the AT822 somewhat noisy when recording quieter environments. I was hoping to step up to something with a better S/N. But it's not a bad idea to get an 825 and save up for something better. Thanks.