Wow, so many people have no clue what the extra memory does and does not do.
1. If a game is not made for 128mb of ram, it won't use it. THATS IT. It will not mess up your game play, and you can always use the delimit patch, which on some games helps considerably. (Very action packed scenes in GTA3\Vice City)
2. You can play on live with the 128mb ram. Why? Because you must be using an original bios with live, which means an original cd, which means that neither the game will be screwed up (cuz of the delimit patch) and your bios will not utilize the other 64mb (cuz you're using an original bios)
3. You can install ram on any version motherboard exept obviously V1.6. (I'm pretty sure you can't piggyback the ram on a V1.6, cuz that would make the module look like 32mb ram instead of 16mb, and I dont think the MCPX is programed to see 32mb increments. Some people claim memory won't upgrade on a V1.4 and V1.5. I can personally say that YES THEY CAN.
4. XBMC, Surreal64, Linux, MAME. These are a few of the programs that use the extra ram. Probably every single emulator for the xbox uses the extra ram, these are the most famed ones.
5. Installing memory is NOT easy. Even if you have very good soldering skills there are still many things that can go wrong. I'm not saying don't try it, but if you have any doubt get one of the memory installers on the scene to do it. If you don't know who they are, then you haven't researched ram enough to know that you even want to upgrade.
These are a few of the things that drive me nuts. So many people make claims about memory upgrades that are untrue. Here are some facts to set people straight.
KingViper