I don't know if I'd say I'm impressed. I did a clean install of DP1 on a cMBP (late 2011). A few notes: a) I hate the new installer. The fact that they've removed the ability to cancel installation or view the log file while installing (by pressing CMD+L, or mousing up to the menu bar) is just silly. Heck, they removed the mouse cursor altogether during installation. What if something went wrong? What would happen then? Or, if the installer was taking unusually long (not unheard of during upgrades), then how would the user be expected to view the log to make sure nothing was stalling the installer? I know the ability to view/save the log file is still there at the very end of installation (when the "completed installation; restarting your computer" dialog appears), but how about during the actual installation itself? It just feels more iOS-like and less Mac-like. It may look slick, but where are the power user features? b) The San Francisco font looks a bit odd on a non-retina MBP. I liked Helvetica Neue better. In some areas, S.F. looks great, I'll grant it that, but otherwise it looks a bit odd... maybe a bit gaudy. I don't know. Perhaps Apple will tweak this more before release. c) Speed, etc. seems pretty much on par with Yosemite. Then again, so far, I've not had an issue with Yosemite, unlike many. Yosemite performs very smoothly on my cMBP. Maybe the impact is felt more with rMBP's? d) Disk Utility definitely is unfinished, especially the partitioning tool. Doesn't work. Hope that's just an oversight. e) I don't like how they changed the "Macintosh Resources" text in "About My Mac > Support" to "Mac Resources." I may be old-school, but I like seeing the (scant) references to the original Macintosh name scattered around the OS. Reminds me of the legacy and roots of the Macintosh. f) Can't believe they haven't fixed the bug in Console.app when you resize the window, the next time you launch the app, it launches in the default size. (Try reproducing this by opening console.app, resizing the window by making it either bigger or smaller, then quitting. Relaunch and you'll see the window has popped back to its' default size.) This has existed as a bug since 10.9, and I've done radars on this for 10.9/10.10. Nothing bad about El Capitan, granted. However, I've always been wary of odd-numbered versions of OS X, because of the pattern I've noticed beginning with 10.4 (good), followed by 10.5 (buggy, bad), 10.6 (very good, refined), 10.7 (incredibly buggy and slow), 10.8 (a refinement of 10.7, improved), 10.9 (sluggish, had weird rendering bugs, TM issues), and 10.10 (smooth, refined). 10.11, unfortunately, falls into the odd-numbered release cycle, so I'll be keeping a careful eye on 10.11 and see how it goes. Hopefully it'll break the odd-numbered pattern. That's my two cents so far!