It’s not cynicism.
The only purpose of the linking the video was to demonstrate the use of a small tip size, thats it. Not an instructional video of any kind, this thread is not "asking for solder technique advice" but "C115 tips in real life".
The first video, the short, shows a tip consistently struggling to deliver heat. The solder wire ends up stuck to the joint multiple times, and they just cut the video each time that happens. They don’t show a single successful joint being made.
OK some useful opinion at least. Maybe the temperature was low, maybe the tip is garbage, no idea. The third joint looks fine, the second joint is probably usable for a mod wire.
The second video shows someone who (in addition to just being a bit difficult to listen to for extended periods of time due to his narration cadence) didn’t understand how to use the JBC-style tip insertion tool, and instead jabbed the tips right into the plastic beneath them…
OK, valid point, but again not relevant to the thread topic.
If you can find other videos better demonstrating C115 use, feel free to add them.
edit: here is a good video from Aixun. Can be done with C245, sure, but much easier with 115.