The PS4 design (and Xbox One) though a disappointing departure from highly capable CPUs with higher clocks was a constraint that couldn't be easily designed around IMO - while being constrained to go the APU route and stay below or around ~350watts and sell for $400 -turned out pretty balanced.
The biggest problem for that generation was the amount of texture data in games, causing game sizes to balloon beyond the bloated PS3 game sizes, that was the result of blu-ray proliferation in the PS3/360 gen. Install sizes, Load times were annoying, so the major changes I(as Ken) would have looked at to fight those issues, would have been to use two HDD bays, with a cheapest/smallest SSD in bay 1 (20GB in size) and a 120 or 240GB HDD in bay 2 for storage, and would then have offset this additional cost by lowering the RAM to 4GB or 6GB of GDDR5. The SSD being a large base technical spec gain would free up some memory reserved for the OS, and help loading and streaming of textures to lower memory needed. Because BC wasn't being offered, historical storage size from the previous gen could be safely ignored IMO.
The 1080p constraint that resulted from the emergence of 4K TVs (in 2013) making 720p too low a target resolution, means that my lowering texture quality (via the RAM reduction and storage reduction for games below a single sided blu-ray 25GB) would be a big problem, so to offset that issue, I would have built a custom ASIC within the Liverpool processor for hard shadow map generation - using the Carmack's reversal technique which is ideally suited to VR and high FPS - which would have freed up significant RAM normally needed for high quality (cascades of) shadow maps, and devs would have then used smaller shadow maps too, to augment those ASIC results to provide soft shadowing.
I would have also looked at another external ASIC that could programmatically have exclusive access to a portion of RAM, for on-the-fly texture generation in under 1 sec, encouraging developers to try and split their textures into two pools, one containing highly detailed unique textures - normal textures - and textures that could be made procedurally generated - probably from multi-layering procedural textures that the ASIC could generate directly into the portion of RAM.
The procedural tex-gen ASIC would lower loading times and memory requirements and potentially provide higher quality mips - via needing generating at 1:1 use scale - but this would come at the expense of more work for the artists and a loss in overall game image quality where more unique texturing was needed instead of lower frequency procedural substitutes.
I might also have considered halving the CPU core count and losing two CUs if it had allowed for reaching +3GHz on the remaining Jaguar cores, especially if it resulted in more L2 cache per core on the remaining cores. The reduction in game data size should have reduced the need for as many CPU cores to decompress data and the inclusion of a dedicated shadow map ASIC should have freed up CU resources normally needed for shadow map generation and comparisons. As the generation progressed, I would expect the SSD to become the only storage in later models and reach a normal 250GB, 500GB at a cost affordable to ship in the PS4 product.
Probably not very Ken like, and would probably have been a disaster compared to what we actually got. I don't think smaller storage and less RAM would have been considered acceptable had the Xbox One launched as it did, although I think the higher CPU clocks versus less cores would have been more popular,
