CO-470 from Golden to the junction of I-25 southbound is under construction right now. They're working on adding a lane, but for now it's a narrow two lanes with zero shoulder space for quite a few miles. Out of all the east bound down hill grades, I found the last one east of Idaho Springs approaching Golden to be the steepest.
Also recommend Monarch if the weather is good. If not, I'm guessing I-70 will get higher priority from CDOT than Monarch Pass. If you can drive big hills, neither is an issue.
Coming through Monarch Pass, if the cable car on the summit of the pass is operating, the view is fantastic up there. You can then either go up to Buena Vista then east on CO-24 to Colorado Springs, go continue on CO-50 through Bighorn Sheep Canyon and stop at Royal Gorge to see the bridge, do the zip line, then continue up 115 to Colorado Springs.