I need some help here...

I've got a 6600GT currently, this one:
SPARKLE Computer

Apparently, Its fillrate is 4000MTps according to wikipedia.
Its got 500Mhz GPU clock and 800Mhz DDR2 ram clock.

The 7600GS, which someone had offered me cheap, can be seen here:
bit-tech.net | 3D Fuzion GeForce 7600 GS - 3D Fuzion GeForce 7600 GS

Its fillrate according to wikipedia is 4800MTps.
Its got 400Mhz GPU clock and 840Mhz DDR.

I have a few questions to ask:
1) My current cards spec is different to that on wikipedia, does that mean that this cards MTps rate is not 4000?
2) There are two different spec 7600GS's on wikipedia, if there are two different specs, shouldnt there be two different fillrates?
3) How can the 7600GS have a better fillrate than the 6600GT, when the 6600GT has a faster GPU and more or less the same ram speed?
4) Should I get the 7600GS?

Thanks, Ant...

1:Wikipedia is not really the best source to get your information from. The manufacturer (In this case Nvidia) Sells the cards to many different enterprise's with there own brands. Think about EVGA or XFX. The manufacturer sends a list of card specs to the company evga (Which is a example in this case) EVGA makes a nice pretty beautifull box around the card with the specs printed on the box.

Apart from that, any card has a manufacturer's manual inside the box. In this case one of nvidia. Nvidia also listed the card specs inside the manual.

These are the real specs, And I dont know what wikipedia is speculating. But they should better ask the manufacturer nvidia for thrustfull information next time instead of typing wrong information on the wikipedia site.

2:There coud be two different specs. Your current 6600GT coud be a overclocked version. Some brands overclock the GPU's which they got from nvidia. Although im assuming youve just got a non overclocked 6600GT.

Apart from that there are also overclocked 7600GS cards. This might be the only reason why the information on wikipedia deviate from the information your reading on the card since there possibly doesnt exist a article about overclocked 7600cards on wikipedia.

3:Since the 7600 card has alot of more features then the 6600GT. That's why. Alot of more pixel pipelines and shaders. And the 6600GT got les ram btw. Besides clockspeed doesnt really matter. Its more about what kind of features does a graphics card have. Also the number of transistors and stream processors take there roll in how fast the GPU is running.

Im not going into detail what features of the 7600 are better in comparisson to the 6600. But believe me, it would be retarded if you should say that the 6600GT is better then the 7600GS.

4:Yes buy the 7600GS. But do check if you motherboard has PCI express. Since im not sure if theres also a AGP version of the 6600GT card. Which means I dont know if you motherboard supports AGP or PCI.