I wouldn't be surprised if there are more .com sites with strong rankings than there are .co sites. But you should remember that:
- there are far more .com sites out there
- .com has been on general availability for much longer, so we would expect some very strong websites to have emerged over time
So although you may see fewer .co sites with strong rankings, that isn't evidence that the TLD itself is to blame. It's just a correlation, and we have no reason to believe that Google treats .co sites as less trustworthy or important than .com sites.
As Richard B has pointed out, ccTLDs send a signal about country-level targeting. If this isn't a priority for you, I would encourage you to buy the better brand name with the uncommon TLD. You are more likely to create a memorable name this way. Sticking with your example, I'd be far more likely to remember
the-example.com. The first name is clear; the second clumsy and forgettable.