after trying to do it through windows store, the update never appeared so I got the mdsn ISO from an unofficial link ;D, its the same image that Microsoft posted officially, same sha-1 so I got the update earlier from ISO, nothing bad happened and I was happy. but also I didn't want to do it much from the store anyways, I better made a clean install because I don't care installing couple apps.
BUT
Update is amazing! 8.1 feels really nice, and I love seeing my wallpapers as my start screen background, it feels so nice! well its also because its batman wallpapers. thats an amazing feature and its nice they added it
The only negative thing about this update... search. its the same crappy search win7 had... thats why i rarely used it. Its boring to have to type more to get the app i want or the setting. I have to be more specific in my search and i find it boring. it puts so many things in one tiny space, it wont find anymore things with just 3 letters.
thats the only thing i hate, i think. also i found a Little buggy the uninstall apps, specially if you have like sync layout and apps across computers? well sometimes i have to restarts to i can reinstall apps for example. but its not like i uinstall many stuff, i just wanted win8 apps to stop telling me i got an update and they didnt want to install.
but everything is good! button doesnt feel so bad, even though i wish my taskbar was clean like before, at least it doesn tlook bad when i hover and i see some pink in my taskbar.
accessing to all apps its awesome! so fast now. that's why I don't mind searching, I rarely used it, and I like using more my mouse for navigating. so its nice to be able to access all apps in an easy way. only click on left bottom corner and then the arrow and I can launch apps easily. I don't think I will fill my start screen so much with live tiles now, specially desktop apps that wont even have a live tile. but customizing start screen is much better.
But I like 8.1, my only complain would be search. sucky sucks once again.
oh also IE11 is of course not the best thing to use, I still do it! but for example if you go to adobe and test the flash, it will say like it doesn't recognize Internet Explorer, if you put the site in compatibility view settings (because apparently compatibility button was removed, and its boring how F12 dev tools have to be opened to emulate another version of IE like 10) adobe site will recognize IE as browser. so it will take time for some sites to fix that. but its not unstable or anything. just the normal for this crappy computer.
and I think its an amazing update! yeah yeah
Edit: I forgot to say, its cool IE modern app, will allow you to open links in a new window, side by side!

. and so easy, right click -> open in new window and bam! you can view to pages. (in my case since I don't have a nice resolution monitor

)