A few years ago, my sniper platoon conducted a similar informal test when we received 8 brand spanking new M40A3's. Some of the guys cleaned after every shot, some after every few, and others only cleaned when done shooting. With one single exception, you couldn't tell the difference between which guns had been "properly" broken in and which hadn't. The only gun we had problems with turned out to be a scope issue, so I don't include that one.
The key I've always found is CONSISTENCY. Consistency is the key to accuracy. No matter how you prefer to clean your gun, make sure you do it the same way each time.