I guess guys like Jimmy Haslip who played bass guitar upside-down throughout their career would have no issue with Stick but, for me, its a HUGE learning curve.....actually, many patterns are identical, like modes ( Ionian, Dorian, Phrygian, pentatonics, etc)...the problem is where the notes fall within the patterns I know from bass dont work to do perfect ascending/descending runs...and the inversions of them, especially with popular basslines, even a simple 12-bar blues walking bassline -- which I can do in my sleep on bass guitar - I have to put a little thought in for Stick.
Also, Im a very competent slap bass player, and Im trying to add the technique to stick and thats proving to be a real challenge