I've read so many overwhelming positive, glowing reviews of Mojave that I went all in on day 1. Well day 2 but close enough. First of all, I'm just glad it installed properly without any problems of note. My initial impressions after just a couple of hours of use is that this is much to do about nothing. Speed: not any faster than .12. Actually, it definitely feels slower. It initially felt like the transition from OS 9 to 10.1. Nowhere near as sluggish as 10.0 of course, but ranks right there with 10.1 and 10.4 in sluggishness. edit: 4k 60fps video clearly has more lag then under Sierra. With Sierra, these videos hiccuped for a bit then resumed playing. With Mojave they hiccup then there's a circular icon then the video resumes. Certainly an additional visual distraction at least. I turned off motion and transparency and that helped noticeably. However, apps still open more slowly than under 10.12. This is very disappointing as I have read that Mojave was supposed to be noticeably faster than H.S. which benchmarks show to be neck and neck with Sierra. Esthetics: I find the new look to be a bit of a distraction. I can't really pin it down to one thing or even several, but the new look is disorienting and doesn't serve any positive purpose. Dark mode doesn't help me much if my browser or other apps aren't compatible. Plus, the default settings render normal use considerably slower. I almost want to use the term 'laggy.' edit: icons default are larger and more colorful. The little msg tab announcing a new track for iTunes for example, is larger, the edges rounded now, and the box is grey. I don't like it as much, quite frankly. Compatibility: I haven't tested every app obviously but steam pinball isn't working properly. It doesn't work in the highest res setting. I haven't used this app in many weeks but still it'd be nice if it worked when I want it to. iTunes and word are definitely slower to start. So far, I don't see what the holabalooo was all about. It looks different, I get that, but .12 seemed to be working fine for the most part and was clearly speedier especially comparing default modes. Security is supposed to be better but that's not a tangible performance gain that I can see and feel right away in use. Not to mention there was a day 1 vulnerability discovered which hasn't been patched yet. I'll be inquiring into reverting to .12 shortly. I thought I would really like the look and anticipated a bit of a speed boost but neither's the case, clearly. This is a very disappointing update. I don't recommend it at all.