[citation][nom]alextheblue[/nom]The newer Xbox 360 consoles have several advantages over older ones, but they are NOT more powerful. CPU and GPU performance have remained the same from start to finish.[/citation]
As far as I was aware the 360 slim had die shrink SoC implementation (rather than seperate CPU/GPU), which allowed far lower latency, less pipe-lining, and had potential for improved clock speeds (As well as lower power consumption). It had to be purposely restrained as to keep in check with the original 360's.
I definitely see a difference in performance (not in gaming graphics but in responsiveness on dash/video/other apps etc) between my original 360, elite & slim.
[citation][nom]alextheblue[/nom]So while I have nothing against upgrades, they won't benefit you to the same degree they do on a PC. PC games have to work on an extremely diverse bunch of devices, and thus are less-optimized but are also scalable (and thus benefit immediately by gaining performance through upgrades). Still... some kind of one-time major upgrade released halfway through the console's lifecycle (perhaps with a new model released at the same time that has the upgrades integrated) still would be very interesting if nothing else.[/citation]
Ah ok. So things like shadow, texture quality, resolution are [would be] relatively fixed? In which case GPU upgrades could only offer improved AA performance?
To be fair, whilst older games wouldn't benefit, as newer games are released (post GPU upgrade) devs could program a limited number of modes for each upgrade (if the upgrades are as simple as dark_lord69 said). A GPU upgrade every 2-3 years could realistically mean 3-4 different modes by the end of an 8-12 year life cycle.