I'm a big Superior King Tut fan for FMQ and like many of the other posters am an Aurifil piecer. I thought Aurifil was better than Superior Masterpiece - less 'fuzzy'. Nor do I like Gutermann very much for the same reason. I haven't tried Bottom line as I'm not a lover of poly.
Just recently I tried YLI Soft Touch 60/2 for paper piecing and really liked it (admittedly I chose it because the colour was perfect for what I was doing), but I was using a very small stitch. I think I will try the Precencia 60/3 for general piecing.
I've also used Connecting Threads for FMQ with success, although I wouldn't go out of my way to get more (they don't sell it here and won't ship, so difficult anyway, lol).
Here is a link to our own member - ArchaicArcane's - price comparison done a little while ago.