Share your experience!
Hi,
I was suffering with same battery drain problem till yesterday but now I have got a solution to make phone faster after ICS update.
1) Take backup of contacts, messages and other valuable data as this will format your phone.
2) After installing ICS once.
3) Connect phone to PC via USB to pc companion.
4) Click Support zone.
5) Now click start button on Phone software update. click on repair phone link.
6) Follow steps mentioned on screen and click next, next, next ... till your phone get updated with new software.
NOTE : keep backup of contacts, messages as this will format your phone.
I did same steps yesterday and now feeling much better with ICS. battery backup has lot more improved. (Now backup is > 24 hrs with all time 3G data ON.)
REASON : Since sony has just updated your old OS with new OS. This was not fresh install. This was making some uncompatible changes which slowed down performance and sucked the battery. This will get resolved by installing fresh OS files.
You will feel much much better after following these steps..
Let me know if this helps you..

Anubhav Ranjan
Sony Xperia neo V user
Hi ascentway,
I am facing similar battery drain issues.
I tried to follow the steps you have suggested. However, when I clicke on "Start" of Support Zone, I get a blank window with only "Back option". Where can I get the repair link?
Also at the top bar, it shows the status "Your phone is up to date", when I click on it, it says checking for update, then another window appears with the repair link,
but the repair link vanishes as soon as I click on it and nothing happens.
Please advice.
Several things which I believe can be benefit to eliminate battery drain issues:
Hope this will help you all.
any update about the wifi problem ?
i have a NEO V and i did the repair from the PCC
It fix most of my problem except for the gaming xperience
i think theres a compatiblity issue between HD games and ICS
and also i cant use my ps1 emulator, it force close everytime 
So I just discovered ANOTHER problem with my Neo V after the ICS update-
I set my phone on vibrate and yet it always rings when there's an incoming call. 
This is getting pretty annoying now.
Anyone know what's up with that?
hi
I have an issue with my sony ericson Xperia Ray. after my upgrade to the latest 4.0 version the network was not detecting frequently. the issue I can see after connecting Data network and Google Play. after several reset only I can connect to my operator network, I regret after my ICS update
please help me out of this. 
Have you tried a 3rd party dialer such as ExDialer from Google Play?
Dude ur Awesome , Seriously
it worked like a charm and my ICs is cool now
thank you !
I've got a Xperia Neo V and after updating it to ICS os on the 13/05/2012 I've had network problem. My phone simply can't connect to any network operator. Im really angry.
I did what anubhav said but it did not help me ,
so i found a temporary solution for this problem , i installed an app videorec from the app store its not that good a recorder but does the job with no choppy recording .
i hope this helps people , and i request sony to patch this issue as soon as possible
link
pls comment back so that i know did it help you too or not.
Thanks