You forget about firmware/software.
What made Dingoo a320 so appealing? Its native os was of a decent quality, emulators and games are still being released for it. What made it more appealing? Ability to run linux - crappy dingux from ingenic at first, totally rewritten opendingux later. Opensource.
What made a320e/a380/rzx50 fail? Shitty attitude from manufacturer, source-code stealing and almost no updates. Ingenic's linux was taken as a base with some shitty mods. Moreover, even ingenic's linux didn't support all features of jz4755 soc. Video processor unit (VPU, almost a second core) - never heard of that. Image processing unit (IPU, hardware image scaling) - ok, let it be a crappy driver for mplayer only. In addition someone decided that bigger screen is better and here comes the incompatibility with a320 software. No wonder no one bothered to make opendingux for a380.
Now, gcw-zero. Without opendingux it would be another crappy console like neogeo x or a380. It's opendingux which makes it a success. Though we don't have proper driver for Vivante GPU, but eventually etna_viv (opensource replacement) will come to the usable state. Ingenic doesn't provide code for it because it's a proprietary licenced technology.
So, before you say that a new hypothetic cosole is a gcw-zero killer look closer at the software. Knowing chineses, I can say that most probably they will make things in a worst possible way. jz4780 has PowerVR graphics chip which is another proprietary thing with no opensource drivers. That means no 3d for opendingux.
So, what are the suggestions for the 'new dingoo'? Well, it doesn't matter what resolution lcd has and how many buttons there are. If the firmware is properly written, it would be a success. If it's another 'we hire some students to adapt dingux for it' or 'we put big screen and Android in it' it would be another fail.
Ok, what matters for me:
- 640x480 lcd screen with hardware upscaling of old 320x240 apps
- 6 gaming buttons abcxyz for sega emulation
- opensource os and user shell (even crappy chinese dingux variant)
- 256 Mb ram (it's more than enough, dingux is not android)