Hi Ghee Chuan,
I've tried the Sophistication at IMM and feels very similar to Sierra Hills at Taka. But I'm not sure if they are indeed similar. Sophistication is cheaper though, so may be a better buy...
Anybody got the Sierra Hills at Taka, please share your experience and if possible, how much you got it for?
I've treid it and it feels very nice -- firm but comfortable! Very pricey though, so would like to be doubly sure before purchasing.