Mt Evans is ok, but usually very crowded. My favorite mountain day drive in the summer is to go up 70 to the turnoff to Leadville, then go south to the turnoff for independence pass and go to the top. Then turn around, come back down and drive to Buena Vista and take 285 back to Denver. It's a great view of a lot of the big peaks in Colorado and you'll avoid a lot of crowds and traffic by doing it that direction.
Don't know the Curtis, so can't really say much about it, sorry. Staying downtown is great though since there are so many bars and restaurants to try.