On paper however LG looks good but o suggest you have a look at both before buying.
I hate UI of Optimus 2x...only because of dual core ..I am thinking about it:.
Even with gingerbread update there is random reboot problem,Some say it is more sluggish than it was on froyo..
I think I wont be loading custom roms. .
You may think I am biased towards arc S..maybe I am
You can also consider the Galaxy R.
Dual Core, good screen , good looks.
Price just dropped down to Rs 22,900.
Flipkart.com: Samsung Galaxy R I9103: Mobile
UI problem: Fixed using launcher
Bugs: Mostly fixed in Gingerbread update
Both of the above can be fixed by flashing custom ROMs.
In short, problems in the O2x are software-related and hence solvable.
On the other hand, Arc S's single core processor and no 1080p video recording, no front cam, and meager internal memory can never be fixed. Plus, it is not future proof (due to single core processor). Avoid it for such a large price.