i think the answer is that it just depends. There are various reasons that movies (and books) are edited for time/length. It's not always because the material cut is bad but because they are trying to achieve a shorter film. Longer films mean fewer showings for example.
Speaking of books, the original "The Stand" by Stephen King was around 350 pages shorter than the Uncut version published later. Now this is content that was originally edited out by the editor/publisher not stuff that was just randomly added later but personally I like it better with than without.
I'd not heard that about The Stand before. Interesting to see it being re-published with such a huge increase in pages. I did read Neil Gaiman's 'preferred' version of American Gods which is a fair few pages longer, but not 350. I enjoyed it but not having reading the 'standard' version I can't compare it. There has been a growing move to releasing new versions of books but not normally with a substantial page increase. I guess it points to a collector focused approach from the publishers.