(Posting again as myself and not accidentally AC)
Honestly it comes down to what you end up using it for. I have an older 360 that I mainly use for media right now and occasionally gaming. The ability to upgrade to a XB1 which has backwards compatibility for most games I play, coupled with both a 4K video player and a UHD-BD drive for $299 is very tempting. Most new UHD drives cost way more than that (I know price will come down).
That being said, as a casual gamer and more media consumer, this hits my sweet spot.