Daz, it all depends on what your main aim for this machine is. They are both underneath very similar machines except PS4 plays at 1080p where as Xbox upscales from 720p to 1080p. Both have voice commands, unfortunately Sony don't make such a big song and dance about it unlike Microsoft.
Currently PS4 and PS4 games outsell Xbox quite significantly so yes more bargain possibly to be had with the Xbox after xmas, although a lot of good bargains just now.
My other half being a games designer has always had both consoles but after trying both as part of his daily job he made the choice for the PS4 as a gamer but we use ours not only for game play but to play blurays and stream catch up and TV services like now TV, nextflix etc.
If your in no rush then I strongly suggest after xmas getting along to a local GAME store and trying out both for yourself, see what games are about, what takes your fancy and what looks and feels better for you.