I realize in rereading Jim's original reference to latency, that I misinterpreted! I NOW understand that the direct output at the headphone jack of a good audio interface will have little to no latency. If that's correct, I can go with the good XLR mic (AT2350) and a Focusrite, and not have to settle for a USB mic. Phew!
That's correct.
Just an fyi, a USB mic is a simple version of a mic/audio interface. It's a mic and audio interface. It doesn't have the features or quality that you can obtain with buying mics and audio interfaces separately. Latency can be an issue with a USB mic just as with a mic/audio interface setup.
Latency is an issue that can be addressed and corrected with either type of mic source.
If you buy a quality product, you may have to deal with latency but it can normally be corrected with just adjusting some settings.
In other words, you don't have to consider latency as a major consideration of your upcoming upgrade.
Charlie