I just wanted to say that the editor runs on low fps on my i5 2.5GHz notebook with a HD7670M, especially when all effects are on, and I have not tested yet a compiled exe with low graphics settings. probably there are tools to refine settings, especially because of the mobile platforms, whose support are not fully finished now. Mac and Ios is in an early state. I will try it as I have time, by checking the example projects for a couple of genres (smaller ones like platformer, and 2 bigger ones for FPS, RTS). I will share them with you.
but defining a min system requirements is a kind of estimation, you can start to develop a bigger project knowing you need years, so imo they are right in case of their main target segment, but made a large step to expand their market towards the indie developers and hobbyists. a few years ago I found UDK system requirements too high, now it is fine, but smaller engines are more hobbyist friendly in this area, having at least one stage technology lag, resulting in lower achievable possible quality, which is not unacceptable in many cases.