Thanks for all the feedback. I did go for the GTX 580. See bottom of this post for an update of how it goes.
About the GTX 750ti; it is much less powerful (in terms of processing power) than the GTX 580 (3 Gb version, not 1.5 GB). Although the 750TI is a newer architecture, it is barely faster than the 460 that it would be replacing. According to the Tom's hardware chart, it is only 3 tiers higher than the GTX 460 whereas the GTX 580 is 6 tiers higher. Also, waterblocks are usually not available for entry level cards. Finally, it would still be more expensive than the GTX 580, not even considering the lack of water cooling.
@Goblinchief
We have limited space available to put my desktop, so it sits about a foot away from my face :P. I guess this explains why I don't want a leaf blower in my ear. It is true that Bethesda games are very CPU hungry. I am using a Core I5 3570K (bought used, traded it for an expresso machine that I had repaired) which should be beefy enough to handle the game.
Update:
I spent a good chunk of yesterday tinkering and replacing the card in my PC. It was a long adventure as I had trouble removing air bubbles due to the placement of my Rads.
The card runs absolutely beautifully! The difference in FO 4 is absolutely night and day. I did not expect to see that much of a difference to be honest. Smooth as butter.
I measured with my kill-a-watt and it idles at about 10-15 watts extra, not that big a deal. Load is about 60-80 watts more.
The curious thing is that the card is actually running cooler than my GTX 460 used to run. Probably the built in full lenght block is better than the standalone I bought for my 460...
Anybody wants a gently used 460?