Comparing (presumed) GPU against PS360 I'd say about 2-3 times, so I have no doubt WiiU games will look better than twins. That said, I suspect at least X720 to be around same 2-3 times more powerful than WiiU, which by itself might not be such a huge problem for developers using current-gen engines who want to port to WiiU. Where I see potential problem is with developers using high-end next-gen engines and pushing them to max for X720/PS4, and then not being able to properly scale them down (or seeing it as not cost effective).







