If DOA6 is a PS4 exclusive, I'll drop the game. Period. Not getting a PS4 just for DOA.
As for the Xbox One holding the PS4 back, bullshit. We're not in the same times of X360 vs PS3 anymore, where they had a completely different hardware design. Porting was extremely difficult because the systems were completely different. Different CPU architecture, different GPU architecture, different memory system, different API. In fact, the X360 was significantly more powerful on the GPU side, and the PS3 significantly more powerful on the CPU side. The PS3 got more beautiful looking games because of two things. Art style from high budget and experienced 1st party studios, and secondly, Microsoft primarily relying on 3rd party studios that generally are not invested in really getting everything out of the hardware, especially not EA at that time. Microsoft mainly had Halo, which is extremely underrated graphically by the way. And obviously, porting either game from one to the other would cause problems, because the console's strengths were in completely different places. The PS3 would not be able to handle the Halo and Gears games, and the X360 would not be able to handle the Uncharted games.
On the Xbox One and PS4 side of things, they both practically use the same AMD APU architecture. The difference is in the amount of compute units and the RAM type, where the PS4 has 18 compared to the 12 of the Xbox One, and has GDDR5 compared to DDR3. Additionally, the Xbox One has its embedded RAM. The PS4 is therefore indeed more powerful on the GPU side. The Xbox One is slightly more powerful on the CPU side due to the slightly higher clock, but the Xbox One is a bit more complicated to program for due to the embedded RAM.
The amount of compute units and memory timings is pretty much the only main things that you need to take into account when porting. Scaling compute units is very easy, and tweaking code for embedded RAM for the Xbox is nowhere near the same issue as changing code from 1 core with 7 sub-cores to 3 full CPU cores... Or changing code from a unified shader pipeline to separate pixel and vertex shader pipelines...