Yesterday I just received the update to 4.2.1 for my TF300T. Have not seen any problems yet. I went into settings and selected the new start up settings, that resulted in me losing all my app folders, the apps were still installed but I have to set up my app folders and screens again. Not a real problem. Some new apps came with the upgrade, and I am still exploring the new OS, but I have no complaints as yet. I bought the keyboard/dock for it and definitely recommend all TF300 owners get one. I have a big 17r laptop from dell and a HP desktop and I hardly ever use them since I got this set up. And this is very portable. My daughter had ipad3 from her school, this runs circles around it. I have also bought lepan s's for 3 people in my family, they are ok but compared to this they are junk. If you do a lot of traveling I recommend you get a wifi hotspot, my phone from sprint has the capability and only costs $20/mo to use, with the wifi I can use this pad anywhere and hook up to the internet.