For that price tag is quite cheap.
Some ppl fail to understand if selected android can't upgrade their OS they don't complaint but when it's Lumia it seems to be a big issue when can't upgrade.

Because RM800 is on the sweet spot for most budget phone buyers.
Entry level of high end phone.

Xperia ray is fine if you can live with the small screen, otherwise go for Xperia Neo. Ah yes, I go no problem with my xperia ray, everything goes smooth. The recent release of ICS caused performance slow down. If you are a gamer, don't update to Sony's ICS, it got bad gaming performance. The user interface is as smooth as gingerbread after some modding.

However, the Xperia U is replacing ray/neo already.
Ray/Neo remains as a good choice if you are willing to trade the dual core processor for a better camera.

As for Samsung, decide yourself...
Example :
Galaxy Y - RM450+-
Xperia Mini overhelms the war without any hiccups.
Galaxy Ace - RM700+-
I rather get Xperia ray ap set. The CPU and GPU is a generation ahead.
Galaxy W - RM900+-
Xperia U eats it alive, with it's dual core.
Galaxy Ace Plus - RM900+-
Xperia U again leads with it's dual core.
Galaxy S Advance - RM1100+-
Xperia sola is just RM999, comes with similar spec.

The most important part, Xperia phones have official ICS update, while Samsung's offerings just don't.
I wonder why people are still willing to pour out extras. Due to marketing gimmick? 

     
Its a good phone if the user don mind 4.x update .
But 4.x seem like important .

thats if only that new version available in the first place. From my understanding those ICS update are available for that phone but different region. The ones without have yet to received their update

No
Go for c1-01 @ 1xx ori