Did a clean install of 6.1 ROM and its working too good.
Overclocked to 729 MHz [gov=Smartass V2] as before and phone working as good as as in CM10. No faster battery drain experienced.
Link2SD is also working good. No problems as yet.
Only bugs faced.
1. Trebuchet launcher started force closing after flashing gapps. [had to install other launcher].
2. The quick settings icon seems to be offset. [Only half of icon visible in Potrait mode. Fine in Landscape mode]