Parker Posey is just a fabulous and awful Dr. Smith. Her portrayal is spot-on every single episode; she takes everything that that 1960s Dr. Smith was and, with a crime-filled backstory, distills it into a self-indulgent, manipulative, and disturbingly believable villain - which is where the awful comes in. Dr. Smith is simply an awful waste of breathable air, and since every tale of science fiction need something bad to battle, Dr. Smith is our primary consistent evil to be overcome (...or neutralized...).
Maxwell Jenkins is wonderful and heartfelt as young Will Robinson - he is the heart of the series and perhaps his best yet in this episode.
The episode itself, Transmission, takes full advantage of Dr. Smith's villainy, Will Robinson's sweetly complex relationships with the Robot and his Father, adds a good dose of action (sci fi creatures are a welcomed sight) and some solid plot advancement regarding the colonists, their planet, and the Resolute and the end result is satisfying and well played.