|Somewhat obscured by the release of the newly complete Pat Troughton serial, "The Invasion", the so-called "vanilla" release of "The Sontaran Experiment" has received little attention from fans wowed by "Invasion"'s black-and-white animation.
Nevertheless, "Sontaran" is hardly an also-ran. It features not only a great story that's the same length as an RTD episode, but a cracking good commentary between co-writer Bob Baker, producer Phillip HInchcliffe and actress Elizabeth Sladen. As the commentary reminds us, "Sontaran", and not "Ark in Space" or "Robot", actually opened the Hinchcliffe era on Doctor Who. It also showcased the first "returning villain" in Tom Baker's era.
On top of all that, it was, like Barry Letts' first story, a technical innovation. Where Letts' "Spearhead from Space" had been the first all-film serial, this was the first to be shot entirely on location.
Consequently, the commentary bubbles over with all sorts of interesting tidbits, both technical and personal, which quite transformed the overall importance of the story for me. While I'd always liked the story, I'd never thought of it as a milestone of any sort until this DVD release.
The DVD also includes a documentary on the Sontarans which runs longer than either of the two included episodes.
Considering that "classic vanillas" now have a lower price point, "The Sontaran Experiment" delivers surprising value for money.