So the gear slips while climbing had nothing to do with my cassette sprockets being worn (which would've been weird since the Jake is new as of this past April). Turns out it was my Shimano chain that was worn for some reason. That reason? I'm told Shimano chains are "soft." Soft like Private Pyle on the obstacle. Replaced it with a steel SRAM chain and case closed.
By the way, I drove the Gaul route last night just to see what scenery I was missing. Saw two roadies (not together). One was cranking up Steely Rd and the other was descending Gaul. Glad to see I'm not the only one who likes the torture.