Gap change in latest month: 451,306 - PS3 & X360
Gap change over last 12 months: 5,204,199 - PS3 & X360
Interesting one given how nicely aligned all the launches are... and PS3 > PS4 transition is exactly the same number of months as PS4 > PS5.
Given the X360 was still a year away from being replaced though, this gap will keep shrinking. I suspect it may fall below 10 million in the next 2 months due to X360s final pre-X1 holiday. And will continue to fall in the following months, but despite the quicker slowdown the PS4+X1 should just squeeze out the overall win probably finishing with the lead in the 5-7.5 million range.