"It is my understanding (will find out in an hour!) that the included charger comes with adaptors for both a regular 110 outlet (with slow charging as described) and a NEMA 10-50 outlet (charges 20/30? miles of range per hour). The expensive wall chargers increase that a little - if your homes circuits can handle it - but at a great deal more expense. Look at getting a NEMA 10-50 outlet installed by your breaker box, should be a great deal cheaper than going the fancy wall charger route."
This should say 14-50 adapter, not 10-50.
Good catch, thanks!