Blimey, people got very agitated over this.

Yes, CO2 will shoot very well. A good CO2 gun will outshoot many shooters.
However. Apart from counting shots, its difficult to estimate when you are running out, and whilst the CO2 caplets are fine, the infrastructure to support bulk cylinders is poor at best. Plus the obvious issues with changes in temperature/pressure.

My club has a dive tank in the corner of the range. So does the Lord Roberts Centre. An old club of mine was next to a dive club and could get at-cost refills.
It simply bears no comparison compared to bulk CO2.
If you want to shoot CO2, you're essentially on your own. Some people do shoot CO2, as evidenced by the empty capsules in the range bin. However, for 60 shot matches, they may not go the length in the same manner as a bulk cylinder will. A 12g capsule should get you 80 shots, but mileage will vary from gun to gun.

If a member of my club asked for advice on whether to get a CO2 or PCP target gun, I'd tell them PCP without a second's hesitation. Why? Well, they can fill it up in the club, there are lots of other people with them (i.e. support, advice, trying guns before they buy), they are well supported from grass-roots all the way up to Olympic level.