I like what you said about the 873 giving that "on mic"
effect.
I found a place near me that has it and I plan
on ordering it on Monday.
I've thought about maybe trying it on guitar cabinets,
out of curiousity. Can loud SPLs damage a condenser
mic? And I should expect a proximity effect with it,
right?
Also, what did you mean by "great off-axis behaviour"?

I've never tried it on guitar cabinets, that would probably give something out of the ordinary versus the typical SM57. The 873r has a high max spl rating, but it could overload a regular mic input unless you use an attenuator. It also requires full 48-volt phantom power, so make sure you have that.
I have tried it for close voice work. It's very clean and sterile with minimal proximity effect. It's not warm, beefy and pleasant up close like a large-diaphragm voice-over mic. It has clarity and distinct accuracy. That's why I like it for dialogue between 2 and 6 feet. The very small diaphragm keeps the off-axis coloration very low. And the pattern works well for front overhead booming angles, keeping the ceiling reflection minimized. If you mount it on an arm or bracket on-camera and slightly out front, this same null zone reduces camera noises.