Ordered my 919 2 weeks ago. I have time to decide but 4 weeks into going back and forth, I can't decide. Fortrex comes with it. Ultrex has he spot lock and other functions that can be used with the lowrance carbons. Yes I am staying lowrance. The hummingbirds are great but I like the lowrance. Have them in my boat right now. Spot lock is the only thing I can see myself using. But I have done with out it for many many many years. i can see the plus of having spotlock but is it really worth the 1k upgrade. Like I said before, lives with out this long?