When James Gandolfini delivered his lines that took place in his hallucinations, he spoke with his more natural voice instead of his "Tony Soprano voice." It's a subtle difference, but definitely noticeable.
When it originally aired on March 19, 2006, it was watched by 9.18 million American viewers.
Vito says Junior "Marvin Gayed" his nephew, a reference to the murder of the singer Marvin Gaye by his own father. Coincidentally, Marvin Gaye's last concert was in Costa Mesa, the same location of Tony's purgatory/coma trip.
Lee is curious how Tony made the jump from selling patio furniture to precision optics. Tony mentioned selling patio furniture on Route 22 as an alternative life during a conversation with Meadow in the season one episode "College," and in a therapy session with Dr. Melfi in season 1.
The credits do not mention the actress providing the voice of Tony's wife while in his coma, though the writers have stated the voice is of a generic New Jersey actress and not intended to be anyone previously featured on the series. Here on IMDb, Wendy Hammers is credited as the "fake Carmella."