Why rollback??

it does tempted me~~

but now my battery life had regain its glory days~~

therefore, no point for me to rollback~
yes.
im using Nilkin hardcase~~ good quality.

bought it from this good seller: https://forum.lowyat.net/index.php?showtopic=3058028&hl=

not final?

Just to clear up this matter, WP8.1 Developer Preview is complete in terms of features. Basically it's locked in feature set. But unfortunately this time it's buggy, if compared to WP8.0 GDR3 Developer Preview. They will release minor updates to address these bugs (lags, power drain). Honestly it's actually pretty stable, just lag & power drain the main issues now. Anyway, Lumia Cyan will add missing drivers to enable some stuff like transmit phone screen wirelessly using Miracast, probably help with the lag & power drain also.

Where got power drain, my battery power increase from 8-10 hrs to 14 hrs..

It normal after every firmware update first few days battery drain abit, since we tend to try out new feature and the phone optimizes itself

Actually I can feel the lag even in games like Temple Run 2 & Subway Surfers!

The only thing that wasn't included in the current WP8.1 build is the lockscreen customisation.
Your battery power increase is interesting honestly but anyway, ppl who experience power drain are all still using Cortana. Hehe. I've been using WP8.1 since the day it day it came out so unlikely my phone still haven't become normal till now right? I'm also not playing with Cortana much now, just using it for alarms, reminders & quick calls.

lol it doesn't seem like nokia anymore XD

3 more days to be officially changed its owner...

imagine Microsoft Mobile 1520...=.="

http://mashable.com/2014/04/21/nokia-oyj-m...soft-mobile-oy/

lol... 

because notification center right?
normal

Yeap, but it's good that ppl are so eager to use developer preview, rather than no one bother. 
This is correct as drivers need to be updated but only come with Lumia Cyan. Also some games need to be updated as well, like those using Unity engine. Basically WP8.1 broke some stuff in current Unity build games so those need to be recompiled & updated to latest Unity version.
Yes this is correct, they need input from us. This is why it's called a preview 

Glad to know its just a bug.

Weird thou as user here still saw problem persisted even on WP 8.1 DP, not fixed I guess.