3. No canned laughter or corny end jokes that freeze frame.
4. The movie did not contain the over the top farce of Klinger - the gag gets old reeeal quick.
5. Trapper was replaced in the series by BJ Hunnicut as Hawkeye's sidekick (one can only assume because Wayne Rogers was more charasmatic than Alan Alda) introducing a whole bunch of bleeding heart stories which were inconsistent with the original book's intention - probably because there's only so many jokes you can make about war and surgery on a prime time show.
6. The movie had a 70s screwball comedy feel that is completely lost in the series - probably because the show was aimed at a PG rated audience.
Seriously, if you enjoy 70s black comedy and you haven't seen MASH the movie what the hell is wrong with you? Get on it.
Here's Elliott Gould again.