remember, a jet is more efficient high up. why drop down to 10k when you can stay at FL290 for longer. in the 170/5 that's about 500lb/side difference in fuel burn at 290kts

and for the super lazy, the 170 will create that glideslope, then follow it down for you. it's great when they tell you to descend via the STAR, and you just put the lowest altitude in and watch the magic box do its thing.