Season four of Hart of Dixie is a shorter season (just ten episodes to accommodate Rachel Bilson's real-life pregnancy so the show could wrap before she gave birth) that ties up the various storylines. The show continues to be very much a primetime soap opera and the focus is on the ever-shifting relationships. Early in the season Lavon and George are forced to work together as volunteer firefighters despite their feelings for Lemon, and Lavon having chased after Lemon to try to get to her before she left on the cruise. Zoe and Wade are doing the will-they-wont-they get together dance. There is also a love square between Lemon, George, Annabeth, and Lavon, as well as Brick having to sort out his love life. So, there is a lot to pack into the ten episodes.
The DVD set is just a made-on-demand set that has the episodes only. There are no extras, which on one hand is not a surprise since Bilson would not have been available to participate in anything that was put together after the show wrapped, but disappointing given that it was the final season of the show. So really, unless you really have a preference for physical discs over streaming, the only reason to get the DVD set is to keep a collection complete, which probably means you prefer the physical discs to streaming.
Overall, the final season is good but definitely rushed. Even so, the storylines are tied up well, and the show uses a flash-forward to give fans an idea of how the main characters turn out. The "fish out of water" plot that was the focus of season 1 was pretty much scrapped as Zoe had committed to staying in Bluebell, so really the only mystery is what characters would end up together. The acting was good even if the writing could get a bit sappy at times (which pretty much is the case with all prime-time dramas that lean toward the soap opera end of the spectrum).