Can't say that I'm impressed with this hire, but I can see what the Jets are trying to accomplish here if they (Jets and Gase) are open to retain the defensive system intact and Gase can develop Darnold, it could work. The thing is I don't really know if Gase deserves the "QB developer or the QB guru" tag.
I was never impressed with his offense in Miami, I know he didn't have great QBs, but he never broke the average line in points for and yards.
In 2016 Phins ranked 17th in points for and 24th in yards
In 2017 Phins ranked 28th in points for and 25th in yards
In 2018 Phins ranked 26th in points for and 31th in yards
Time will tell, thumbs down if I were a Jets fan right now.