Are these two sentences correct?
This is as good as ...
This works as well as ...
This one is as good as the other one.
This one works as well as the other one.
Your edits are correct.
Good is an adjective and describes nouns, in this case the subject of the sentence (this).
Well is an adverb and modifies verbs, in this case works.
"As good as" an adjective that is used for equality. "As well as" an adverb that is used for equality.
"This is as good as..." is right. "This works as well as..." can have 1000 substitutes and it's not right.