I think one thing worth considering is the crazy amount of bundles that are currently for sale in the UK. There is a reason that the PS4 is in such a bad place on that list and the XB1 is completely missing.
The PS4 has 7 different bundles directly sold by amazon, each one counts as seperate sales. And there are a ton more not sold by amazon directly.
http://www.amazon.co.uk/Xbox-One-Console-Essentials-Edition/dp/B00KJFDSLE/ref=zg_bs_2785502031_2
The XB1 has 27 different bundles directly sold by amazon, each one counts as seperate sales. And there are a ton more not sold by amazon directly.
http://www.amazon.co.uk/Xbox-One-Console-Essentials-Edition/dp/B00KJFDSLE/ref=zg_bs_2785502031_2
Looking at current sales where we can see past the top 100.
The PS4 has 2 bundles in the top 100 and the XB1 has 4 bundles in the top 100.
The PS4 has 6 bundles in the top 1000 and the XB1 has 15 bundles in the top 1000.
Currently the top 6 PS4 bundles have the following rankings.
41
65
108
120
836
983
Currently the top 15 XB1 bundles have the following rankings.
54
58
89
97
102
145
223
303
317
412
615
654
761
824
874
I don't really know what the cut off for significant sales is. I don't think anyone knows. But whether it is the top 100 or top 200 or top 300 it seems the ps4 and xb1 are very much currently neck and neck unless there are huge gaps between skus in similar places.
Obviously we can't look past the top 100 for last weeks numbers. But I'd imagine it's very similar with the ps4 having the best selling sku but the XB1 having more sku's that are selling decently.