A belated welcome to you, Perankh! It's always wonderful to see another 'cousin' arrive.
The Adam storyline has never been a favorite of mine. Compared to the rest of the series, it's very boring and weak where plot, dialogue, and creativity are concerned. I agree with you that it relies too heavily on Frankenstein for its inspiration. While I've enjoyed watching and re-watching the classic Universal monster movies since I was ten, I was never able to work up much enthusiasm for the Frankenstein films (and unfortunately, that's the longest series.) The idea of a man-made human being is so much less mystical than ghosts, shape-shifters, or vampires. Coming to this after the quality and excitement of 1795 only heightens my disappointment. Looking at some of the ideas that DS uses in the future, I do think that the writers could have tried a little harder here.
However, there are some nice aspects to it: the introductions of Professor Stokes and Nicholas Blair, Angelique's aging scenes. I do think that bringing in Adam was an interesting way for the writers to deal with Barnabas's 'affliction' and his evolving character.
Actually, watching this the second time around hasn't been as painful as I'd anticipated. I think I've gained a greater respect for Robert Rodan's acting, particularly during Adam's early stages. It must have been difficult to create a plausible character using only hand gestures and facial expressions, but he pulled it off very well. In fact, I think Adam is a more human and sympathetic character than even Karloff's creature. If it came down to whether or not I would watch this storyline a third time though, I think I would stick only to selected episodes and Robservations.
ProfStokes