I am a beginning quilter and I went through the same thread confusion. heard so much about King Tut and ordered some and got this enormous spool. I felt like a fool. Then I went to Joann's all set to buy Gutterman but they only had polyester. So at least, I went on eBay and bought 2 sets of Aurofil thread a 50 wt for machine work and 28 weight for hand quilting. They are a little goofey on my Husvarna machine because they sit upside down on the plastic knob but my machine seems to like them.
I don't think the world would come to an end if I used polyester thread but I have always used cotton or silk for garment sewing mainly because my Mother ( a pattern fitter and professional seamstress) always did.