In response to how many people shoot real Colts, I would venture to say less that 8% of the shooters use real Colts all the time. For one, they are a little on the pricey side. When you can buy 3 Rugers (also American) or any of the clones for the same price, they are not in many folks budget. If you want new ones, the wait can be very long while they also hold your money.
I have 6 pairs of Colts but I prefer shooting my 3 screw Rugers only because they fit me better. I use the Colts occasionally only.