I may seem a bit harsh with my ratings, but I personally think, that I may not be strict enough 
There are some **** star films I`ve seen, but it doesn`t necessarily mean, that those are the best. "The Mother and the whore" (***3/4 / ****, the last time I saw it) for example would rank higher than some **** star films. The rating reflects my overall opinion of each single movie. So sometimes I can watch a great film with minor flaws, which is better than a perfect one 
The Lumiere`s shorts were really astonishing, but I may have been a bit weary, when I afterwards watched some other shorts. Imo it doesn`t make a big difference if one watches five feature films in a row, or 5 short films. In both cases the concentration doesn`t suffice to watch them all properly, to the disadvantage of the films seen last. And it`s even more difficult, if the films resemble each other. 
After reading some good reviews on the shorts by Robert W. Paul, James Bamforth, James Williamson, and George Albert Smith, I must see them again. But I think the "camerawork" is best in the Lumiere shorts.
As for Bartas, those were my first two films by him, which i saw in a row, and i would love to see more. It was a great movie-going experience, and I didn`t really understand the problems with his films. They seemed very simple to me, the narrative was clear, and the symbolism wasn`t obscure. 
I`d like to know, where you saw some of his other films, and if they`re available anywhere (with subs?).