Not true. The human eye works at different frame rates dependant on the human. If the eye was limited to 25fps then we wouldn't have monitors running at 60Hz or 75Hz - even up to 100Hz. Even when you are no longer visually noticing the difference you can still notice a improvement in smoothness of gaming above 25fps. Also the 4850 (especially the 512MB) is now a little underpowered in more than just Crysis. We have the resource hungry GTA4 to consider too! My 1GB 4850 isn't the best in GTA4 although I am lacking RAM (only 2GB) so that has a big effect!
You're right. I have 42" Plasma TV and I think it runs 50Hz because I can see the subtle flicker. 4850 is enough to run games at highest settings (maybe except Crysis at 1920x19200), but it is still the best value gfx. If you take 2 4850s in CF, you are getting about 30-50% better performance than a single 4870 (for about the same price). The reason why 4850 is the best bang for bucks gfx is because the 4870 cards are slightly overpriced (sinse they are the latest). Whenever a new card arrives, the older one drops in price. I'm thinking of buying a 4850, and when it becomes a wee bit slow, buy another "bang for bucks" ATI card (perhaps it would be the 4870 this time?) and I'm settled for another 2 years without wasting any money. I'm told that GTA4 recommends a quad core CPU as well!
