I have major issues with taking the lane to the extent of positioning where a driver sits in a car. Yes sometimes you need to, but generally it's bad advice.

1) It's likely illegal in states that have laws pertaining to bicycles that state the cyclist must ride as far to the right in the "road" as safely possible. That means on a shoulder if available, or the lane of traffic if needed.

2) A LEO can readily site you for obstructing traffic. And IMO, they'd be correct.

3) It's clearly dangerous when cars use the right turning lanes to pass you. Maybe in Memphis they are polite enough to not do so, but try it in NYC and they'd run you over, especially at rush hour.

4) Positioning yourself that far left into the lane is making a somewhat ambiguous statement that you might be making a left turn.