If you're looking to find an HDTV for your gaming needs, you may already know there are three important criteria.
1. Input lag (directly affects gameplay 100%)
2. Motion performance (gameplay 50%/eye candy 50%)
3. Contrast ratio (eye candy only)
In choosing a TV that fits your needs, always ask yourself if you can give up slight performance in one ranking if that means a huge boost in another. For example, if you're really going hardcore and you would not even budge an 1ms for the input lag, then yes, the Sonys will be the best TV for you. If you value both input lag and motion performance and would like a TV that is balanced on both ends, then either the Samsung F6000 or the plasmas are the alternatives. If you also throw in contrast ratio into the equation, then you need to look at the plasmas hard.
I personally don't like the Sonys as gaming displays because their Motionflow Impulse is still broken. If you do choose to go with a Sony, the W650B is already an excellent starting choice and throwing big money at higher models will only bring miniscule improvements. Let me tell you this.
1. You won't get improved contrast ratio by going with a higher end model. Sony's edge-lit dimming is relatively effective, but in the end, it's still not worth their asking price.
2. You will get better calibration options (no CMS though) by buying a more expensive model, but this only applies if you're willing to pay extra for a calibration.
3. You will see improvements with Motionflow Impulse. (meaning you can go brighter) But I still say only the top end model, the X950B can make practical use of it because of its FALD design. The others may prove too dim for you.
If you want a general primer for gaming on a Sony, check out Fudoh's excellent review of the W650a. It's a last year model, but most of what he says in that review still applies to the W650b. Of course, I will have to politely disagree with his statement that the W650a is the best gamer's HDTV in 2013. Not when I am an owner of the Panasonic S60.