Like many here, I have upgraded my 2011 MBP to Lion on the first day of its release. The upgrade process was painless and Lion experience has generally been great. However, there are various quirks and annoyances I have with the OS. Some are bugs and rough edges around the OS, which is to be expected. Others are just the new default settings that may look like bugs. First of all, booting takes on average 10 secs longer than it did. Under Snow Leopard it took 32-35 secs to boot up, now it takes 40-45 secs. However, it takes faster to log in and fully load the desktop (I have 2 by default), the menubar and the dock. Also, the battery life seems to have decreased by about an hour. I do not get over 6.5 hrs whereas I used to get 7.5 (doing basic browsing/productivity) under SL. OS X Lion Bugs/quirks (will be updated as more comes to my attention): 1. Upon boot, when you get to logon screen, the keyboard doesn't light up unless you manually use the backlight control keys. Only upon entering a password and logging in, the keyboard lights up. 2. Upon display sleep, the display cannot be reawaken by touching the trakpad. Instead you need to physically click it or press a keyboard key. Not sure if it's a setting or a bug. 2. The Mac App Store feels very sluggish. Constant beachballing, every time you open the app, try to switch "tabs" or enter app info pages. 3. Dashboard (when it's not set as a space) sometimes reloads upon access. 4. Sometimes the Finder would close all windows and, upon reload, the gestures won't work anymore. 5. When entering Time Machine the finder windows are resized, but are not resized back to normal upon exit. 6. Time Machine now backs up more frequently than it did in Snow Leopard. As a result, it now frequently puts up an exclamation mark to tell you that there is new stuff to back up. This seems more like a different backup behavior than a bug. All being said, I like Lion a lot. I love how they got rid of scrollbars and included the ability to resize windows from any side/corner. Also, the new way the OS handles spaces has become VERY helpful and has increased my productivity by a fair amount. On the other side of complaints, I do not like how hard it has become to "Show Desktop". the three finger + thumb outward pinch) gesture is really painful and, despite my best efforts to learn it, is still hit or miss. This is, perhaps my only complaint about gestures in Lion because just about every other gesture can be changed, except this one. Additionally, I am baffled by the addition of "Launchpad". I have no need or desire to use it, so I disabled the gesture right away. Please share your experience. Do you experience the same bugs and/or behaviors in Lion OS? Are you experiencing other bugs? How/when did you upgrade? Did you do a clean Install?