I bought a Bernina L450 last June. After 25 years with a Singer 3-thread serger ), I am thrilled with this one. Initially, I went into the dealer to look at the Babylocks intending to buy one with the air threading but once the clerk showed me a few different ones I changed my mind. The Bernina L450 is so easy to thread that the air threader wasn't worth double the amount it would cost to buy it. The best part is that it stitches like a dream!