I came across an interesting comment the other day, in which someone suggested that you shouldn't update to the latest version of Mac OS because Apple are deliberately making your machine slower with the updates in order to make you get a new one. I've been using a 11" MBA (late 2012) for almost 3 months now and I had no problems so far. I check every now and then to see if there's a new update to be made, and if it is, I do it. I know that the comment was probably referring to the big updates, but still, I wish to know more from older Mac users. I don't use the MBA as my primary machine, but I would like to keep it as fast as it is right now for a few years. I would like some feedback from older Mac users who have been updating for years and have surely seen differences from version to version.