I've got both WPT Season 1 and 2.
They're both worth getting, although Season 1 is brutally expensive now for some reason (it's $80+ CDN where I am). I ended up buying Season 2 using bankroll money and it was great. Then they started showing the episodes on TV...but I did get to watch them all before my friends did.
Season 1 is pretty good too. Worth $80? It is for someone who likes poker - I'd rather watch poker than re-runs of Friends on TBS, that's for sure.
There is no additional footage at all. What you saw on TV is what you get the DVDs. There are no commercials, but there is a five second WPT ad where the commercials would go - you will get good at fast forwarding when watching these things. Also, I like fast forwarding through the Mike Sexton/Vince Van Patten banter - I'm still not convinced that Vince Van Patten knows how to play poker...
As for the extra features, they're not that good. If you know anything about poker, the poker corner tips are worthless. They have some player bios, but they're pretty useless too.
If you're gonna pick these up, get them for poker and not for the extras.
K.