Almost certainly? Why would your wi-fi driver behave differently than that of most other people, including most reviewers of the 15", who don't have the issues with battery life that you do?It has almost certainly nothing to do with my setup. Rather, it might be something that might frequently change within the environment without being obvious: wifi driver came into suspicion.
Line of thought is: if it has something to do with wifi, a user wouldn't necessarily notice. Congested channels, jumping frequencies, etc.
This would explain the observed inconsistencies.