I will say, you need to use high quality lead-free solder when you could get away with decent lead solder. The cheaper lead-free stuff has been junk in my experience.
Do you have any recommendations? I was soldering earlier today and noticed a particular joint wasn’t flowing well at all. I looked over and had grabbed the lead-free solder from my spool holder. All the other joints with my crappy Radio Shack leaded solder were fine.
I don't. I have a roll of lead-free that works OK, but I got it so long ago that I don't know. I think it's an off-brand that doesn't even have a name on it, or the sticker peeled off. It's still more temperature sensitive than lead, but not bad. I think my better quality lead roll is from them too. I wish I knew the name so I could order more of each.
On a related note, I've had terrible luck with any of the Chinese solders off of places like Temu or Banggood. Even the lead ones were junky.
I'll second the Kester recommendation, the stuff is a bit expensive but if you've used bad solder you know it's worth it! I'm using Kester 275 on the bench and have been very happy with it, and as it's a true no-clean flux, it's a bit less messy than Kester 44 without much performance difference (lead free vs lead differences are real still- Lead-free is still not as easy to work with, but the world went lead free so my bench did too). You can find some comparisons here (since kester's website is down currently for some reason) https://www.jameco.com/Jameco/Products/ProdDS/2188246.pdf
Chipquik works fine. There’s probably better stuff but it is consistently good and doesn’t seem to go bad (i can’t tell much performance stuff between a roll that’s old enough to have the label rubbed off and a brand new one).