If I'm just putting along I'll ride in a bike lane. I'm slow enough to not be a threat and can react faster and easier to people who 'ride bikes' but aren't 'riders'...yep there is a difference.
If I'm out in 'performance mode' I leave the bike lanes to others. I'm not willing to put others at risk, or myself for that matter, by riding at a high rate of speed and mixing with the variety of bike riders that are riding the lanes.