Santa Cruz Tallboy vs Hightower

Santa Cruz runs S through XXL on both bikes, and the Tallboy and Hightower share near-identical reach figures size-for-size - so your size doesn't change between the two. Where they diverge is head angle and stack: the Hightower sits roughly a degree slacker with a slightly taller front end, which subtly shortens effective top tube in the riding position. The Tallboy's steeper seat tube angle puts you more directly over the bottom bracket on climbs, which suits its short-travel intent. If you're between sizes and pedal-focused, lean toward the Tallboy in the smaller size; if you prioritize descending on the Hightower, go up.