FWIW, my DH suffered Acute Mountain Sickness on Pike's Peak; luckily I did not, as I was the driver. (Men are more prone to it, we were told. We had come from an area about 500 ft above sea level.) We made it to the top and were about to take the elevator to the deck when he started stumbling and looking green; and asked to leave immediately. I recall that we had to stop 3 or 4 times on the way down so that he could throw up.on the side of the road. He was OK in Colorado Springs proper, but the Peak did him in. I'd say that if you don't know how you respond to high altitude it is best to bring a basin of some kind along on the drive up there, JIC, and have a woman drive if possible.
Last time we were in Colorado Springs was for a skating competition at the Broadmoor Arena in early April of last year. We rented our car in Denver, but 2 other couples we know got small cars at COS and were warned that they did not have adequate power to be driven up Pike's Peak.
If you drive from the Denver Airport to the Springs it is shortest to take the E470 toll road, which I gather is not something locals usually do if they can avoid it. The toll-by-plate charge is pretty high, and transponders from most other states will not work. (Also, it's tricky to stop for gas heading into DEN from the toll road; you have to get off one exit early, at E 64th Ave, then gas up on Tower before rejoining Pena into the airport.)