Peace Guys ..
@nishant71
W550i n K750i are both good
since you are a old SE user you will like both of them
Just think what u need from them
>If u need 2MP Camera n expandable memory get k750i
>If you need more of music .. radio n mp3 .. & 256MB is sufficient for you get 550i n have fun
not to mention the good headphones u get with walkman series
regards
mobilegeek