I've tried to warn people about them. I got a 10 pack early on while learning and it almost made me give up the hobby. Classic n00b mistakes? Some, but after I set that filament aside in a drybox, I had almost no problems. The only mistakes I made with those other brands were due to strategies I developed to rescue prints from IIIDMax's garbage. I must have used 10-20 other brands over the next year, revisiting the cursed spools occasionally.
I thought I could relegate the leftovers to my 3D pen. Somehow that satan-spawned plastic jammed it up. The pen is basically a soldering iron, a motor, and 2 gears. I've fed strips of PETG bottles cut by hand through it. The filament wasn't precise enough for my no precision 3D pen.