[XPERIA SOLA OFFICIAL ICS Build 6.1.1.B.1.10 - India(ASIA)]

This is the Indian ICS Firmware 6.1.1.B.1.10 for Xperia Sola (MT27i)
I downloaded it from SEUS and packed it using Flashtool..

MT27i_6.1.1.B.1.10_India.part1.rar
MT27i_6.1.1.B.1.10_India.part2.rar
MT27i_6.1.1.B.1.10_India.part3.rar
MT27i_6.1.1.B.1.10_India.part4.rar

I would suggest doing a factory reset after flashing...
I did a factory reset..and now I have absolutely NO LAG...IT's SMOOTHER THAN FREAKIN GB

Benchmark comparison

Don't forget to hit thanks. 

After downloading all the files, extract them to get the ftf, then flash it using flashtool.

http://forum.xda-developers.com/showthread.php?t=1914264