Ok, just to inject a little bit into this discussion:
If you were unaware, Demigod's engine is basically Supreme Commander's. Supcom was ported to the Xbox 360, however, it was rather limited from everyone I've heard who has played it on both PC and Xbox. Limited size maps, poor controls, no-FA (which is not so much the Xbox's fault). Specifically, much of the limitation appears to be due to the memory. The 360 has 512MB for all the application memory, textures, and EVERYTHING. Demigod seems to use more RAM than the 360 has, which I'm not surprised by.
Consoles are crippled for games using this engine. They will work, because a lot of Supcom's underlying base seems to be directly using the same libraries from Microsoft which can target either Xbox or PC. I seem to recall specific mention of the networking being the same sort as the Xbox would use. If true, then the assumption of the original poster, is quite incorrect about networking potentially being better on the Xbox. They also decided to calculate the simulation on all computers, which has it's plusses, but also has a big minus in that the performance is the slowest one. Granted, on Xbox that wouldn't matter, they are all equally slow.
As for the 360's CPU. It would do horrible compared to a PC if there were a direct port. It's why Supcom-360 needed a lot of translating of the lua that the engine uses on PC into compiled code. The Xbox basically has no branch prediction, which is a huge portion of most code. It's a lot simpler to design without, but it's one of the important things that drastically improves performance, especially on code with lots of branches like many compilers generate (and have to). Plus the CPU has to go through the GPU for memory access.
In terms of graphics, the chip is roughly a few generations ago in terms of PC graphics cards. Additionally, it suffers from having to share bandwidth with the processor. Compare a older desktop from a while back with Dual Channel DDR2 400, and a 7800GT. Memory bandwidth is 6.4GB/sec-CPU + at least* 54.4 GB/sec-GPU or over 60GB/sec to the 22.4GB/sec for all of the Xbox's needs. Based on production times, that 7800GT probably has more performance than the Xbox's GPU. Mind you this is a rather old desktop (original 939 Athlon 64). It's basically like having part of the reason why Intel Graphics based computers suck. (Granted, with a better graphics part.) If there is any better looking stuff on the Xbox, it's only because people have been very careful, and looked specifically at it. Compared to a decent or good PC, the raw power is rather low. In fact on Xbox, usually games are rendered at lower resolutions and then scaled up to fit the signal. Kind of sad about consoles talking about 'HD' stuff when you realize they aren't capable of it with many modern graphics.
From almost any technological standpoint, the PC is MUCH better equipped to deal with this game, nevermind the controls.
(*I couldn't directly find reference specs for a 7800GT, so those are of a vanilla 7800 from nvidia's site)