So it seems it really does come down to just preference?
I've been stick and MIG welding for years but nothing beyond hobby or the odd favour job. I recently picked up a new-to-me machine that is much bigger than my previous 110v mig and seperate 225a stick machine. An airco unit that does mig, AC and DC stick, and Tig (with the right equipment)
I remember when I first bought my 110v machine a decade ago, it came with low quality flux core wire. Coupled with my brand new inability to weld and the underpowered 110v machine, the flux core was a messsss. Once I put gas on that machine it was like night and day and swore I'd never do flux core again.
Fast forward 10 years. I'd say I'm a fairly intermediate welder with enough knowledge of an ignorant hobbiest BUT with a taste for YouTube teachers now. I've seen many YouTubers use flux core. Chucky2009 uses it often, sometimes explains why but not why he chose flux core. Also Jody from welding tips and tricks, same fiasco.
So it raised the question.
I've also noticed a drastic difference in price between what appears to be crap flux core and a good flux core...? Nearly $80 for a big roll (this airco only takes big rolls, unless I build an adapter)
Right now it has .030" wire. With about somewhere between 1/8 and 1/4 of a roll left. I might to go .035" once it's gone.
The machine runs really well after I cleaned everything up, but I don't often get the nice bacon frying sound when I have the heat a bit higher. More of a popping than a frying. I usually have to have the feed knob maxed. Maybe trying to weld too much with too thin of wire? On a bit lower heat on thinner guage it sounds fine. But otherwise, nice bead, good penetration, clean, fairly happy.