yeah i use MC64 too, I only upgrade on the full versions, 139, 140 not 139u1, 139u2. A lot less steps, and not really worth it to get the minor upgrades for the small updates.
hmm.. I cant's say I've seen any real benefits to my updates since I started not too long ago. It had to do more with an obsession of being up to date in case new games were playable.