[Shini44]

getting new portable AMP (UHA-6.MKII) and it does offer an upgrade for the standard chip and replace it with OPA627AP for 50$ yet can any one tell me how good is this chip and what should i expect from it

 

[wuwhere]

That's very expensive. On my Neco V2, I swapped the original opamp with an OPA627. I thought it was a little darker.
 
Here's some comparison.
 
http://tangentsoft.net/audio/opamps.html
 
There are also fake OPA627 out there.
 
http://www.head-fi.org/t/316937/fake-opa627s-in-the-wild