Hardened nozzles - worth it or just hype?

I went through the same debate last year when I tried a spool of carbon fiber PLA on my MK3. Bought one hardened nozzle just for that job, printed maybe half a kilo with it, then swapped back to brass and threw it in a drawer. Swapping itself is easy enough, but every time you pull a nozzle you're basically redoing your first layer setup, and I got tired of babysitting the bed z-height on a printer I otherwise never touch. If your swap schedule is once or twice a year that might not bother you, but it bugged me enough that I eventually left the hardened one on and just forgot about it.

On temps, my experience matches the 'bump it a bit' crowd. With the steel nozzle I run PLA about 5 degrees hotter than I did with brass and it comes out fine. PETG I didn't notice any change at all. Surface finish looks the same to me on everything I've thrown at it, mostly functional parts, so if you're chasing glossy cosmetic prints your mileage may vary. One thing that pushed me to just leave it on: glow filament chewed up my brass nozzle faster than I expected, and I only print that stuff once a year too. The hardened one shrugged it off. Honestly the wear on brass from occasional abrasive stuff is slow enough that you could ignore it for ages, but once I already owned the hardened nozzle there was no reason to keep switching back and forth.

I landed on the opposite end of this and just left a hardened steel nozzle on my MK4 permanently, and I've been happy with that for over a year now. The first-layer fiddling that comes with swapping is exactly why. Every time I pulled a nozzle I'd spend twenty minutes with the live z-adjust relearning the height, and my PLA would still be a hair squished compared to before. Not worth it for a spool or two a year.

As for quality, I noticed nothing after bumping my PLA temp up about 5 degrees when I made the switch. Benchies look the same, stringing is the same, overhangs are the same. The thermal conductivity difference is real on paper but in practice it just fades into the background. The other thing that pushed me this way is that wear is sneaky. A worn brass nozzle doesn't announce itself, it just slowly fattens your extrusion width and degrades your dimensional accuracy until you're chasing ghosts in your calibration. With the hardened one I stopped thinking about it entirely. They're cheap enough now that the pay-more-sit-there argument doesn't hold much weight for me.

This is making me think about my own setup. I printed a few rolls of that glow stuff last winter thru the regular brass tip that came with the printer and never thought twice about it. Now I'm wondering if the little hole in the tip is already worn bigger and my prints are slightly messier than they should be without me noticing. Is there an easy way to tell when a tip is worn out, like a visible clue, or do you just kind of guess until prints start looking bad?

The trick I landed on years ago, back when we used to keep a whole spare hotend loaded with filament and ready to go, is to just build a second one. Got a cheap steel nozzle on a complete spare hotend sitting in a drawer with the cable alredy zip-tied nice and short. When abrasive season rolls around it's a five minute change, not a teardown. Sure, you still touch up the first layer, but you're not starting cold. Cost me next to nothing doing it that way instead of buying the fancy stuff. Works the same on every machine I've owned since the Mk2 days.

Update: went with the spare hotend idea from earlier in the thread, threw a steel nozzle on a cheap backup and it just lives in the drawer til abrasive season. That part is solved. Still stuck on temps though, my first layers with the steel tip look a touch under-extruded. Do you folks actually bump the temp a few degrees, or just keep nudging until it looks right?