One gets the impression that the editors of L used the good stuff from the W and substituted their own, much better material when they encountered some of the bad stuff.
( One ( ( ( gets ( the impression ) ) ( that ( ( ( the editors ) ( of L ) ) ( ( ( ( used ( the ( good stuff ) ) ) ( from ( the W ) ) ) and ) ( substituted ( ( their ( own ( , ( ( much better ) material ) ) ) ) ( when ( they ( encountered ( some ( of ( the ( bad stuff ) ) ) ) ) ) ) ) ) ) ) ) ) . ) )
(ROOT (S (NP (PRP One)) (VP (VBZ gets) (NP (DT the) (NN impression)) (SBAR (IN that) (S (NP (NP (DT the) (NNS editors)) (PP (IN of) (NP (NNP L)))) (VP (VP (VBD used) (NP (DT the) (JJ good) (NN stuff)) (PP (IN from) (NP (DT the) (NNP W)))) (CC and) (VP (VBN substituted) (NP (NP (PRP$ their) (JJ own) (, ,) (ADJP (RB much) (JJR better)) (NN material)) (SBAR (WHADVP (WRB when)) (S (NP (PRP they)) (VP (VBD encountered) (NP (NP (DT some)) (PP (IN of) (NP (DT the) (JJ bad) (NN stuff))))))))))))) (. .)))
The movie mashup editors were surprised how well the lifted L material meshed with their contributions. 
( ( The ( movie ( mashup editors ) ) ) ( ( were ( surprised ( ( how well ) ( ( the ( lifted ( L material ) ) ) ( meshed ( with ( their contributions ) ) ) ) ) ) ) . ) )
(ROOT (S (NP (DT The) (NN movie) (NN mashup) (NNS editors)) (VP (VBD were) (VP (VBN surprised) (SBAR (WHADVP (WRB how) (RB well)) (S (NP (DT the) (NNP lifted) (NNP L) (NN material)) (VP (VBD meshed) (PP (IN with) (NP (PRP$ their) (NNS contributions)))))))) (. .)))