i can go for both just wanted know which is better interms of roi
Well, to enjoy Android, you need a large screen (>3.7 inches). But some people find large screens difficult to work with. If you're that kind, then Live with Walkman is for you. All of Sony's 2011 Xperia phones (and Live with Walkman) will get ICS update. So no worries there.
Xperia Pro's QWERTY keypad is a plus,
but do you need it? Do you type out long and frequent SMS/email/IM/whatever? Can't you type using the touchscreen? You need to think about that, then make up your mind.
If no keypad is ok, but you need a bigger screen than Live, get the Xperia Neo V.
Why aren't you considering other brands?
They all have the same chipset (Qualcomm 1GHz CPU with Adreno 205 GPU). So don't bother about performance differences.
Return on Investment? For a phone?
What exactly do you mean? How long it'll last?
You do realize that any phone you buy will be obsolete within 2 years, tops.
Edit: You shouldn't have posted here. Buying advice section is [here]. Get a mod to move it.