I didn't own one at the time, but since picking one up this year I've quite enjoyed it. Haven't fully explored its library yet, but I did enjoy Quantum Break and Gears 4 so far.
The graphics don't seem that much worse than PS4 for me, and it does have most of that gen's best third party titles like Witcher 3, Doom Eternal, Nier Automata, etc.
I'd give it a solid 7/10 personally.

Played it way more than my PS4.

One X was amazing hardware.

Overall a great console. Lots of games, lots of features, GamePass. Titanfall 1.

Yeah I will say, the One X does seem like a much better midgen refresh than the PS4 Pro, at least in terms of hardware.

The One X was a $100+ more expensive and launched a year later. Being much better is a no brainer with that in mind.

For instance PS5 DE was also a $100 more expensive than a Series S, but it launched simultaneously with it and was like 3-4 times more powerful. The One X was imo a waste of money as you only had to wait 3 years to get much more capable and advanced consoles at similar or cheaper prices.

If I lived in a place where all I have is an Xbox One and no other choice, I think it's good enough on its own with the games it has.

No, but it did have Rare Replay, so it earns points for that.

Are you comparing Xbox One X to Xbox Series S as well? Xbox One X would go on sale sometimes for $400 and went on sale for $300 in its last months on the market at most places to clear inventory. 

Xbox Series S is more modern than Xbox One X. But One X has the physical media advantage and typically has higher resolutions. Series X is obviously way more capable than One X or Series S.

The XBone is just barely a good system.  If you judge it by exclusives alone, then it sucks.  And I've played mine less than my PS4.  However, I've also gotten rid of my PS4 while I'm keeping the XBone.

When my mind is in retro gaming mode, I just think about things differently.  I really, really hate that the PS4 is not backwards compatible with the PS3.  That's not much of a problem with the XBone.  Also, I still have a huge CD collection, not to mention DVDs and Blu-Rays.  Almost all of the PS4 games I want to play are on the XBone too, and the ones that aren't are on the Switch.  And most of my PS3 games can be purchased on Xbone or Switch.  In the long term there is not much reason to own Playstation.  Currently I've got a PS2 that I still play (and a PSP I haven't touched in a long while).  The XBone is just a better machine when you think about retro gaming and long term use.

Xbox one is a good system, they just had bad management when it came to making the decisions of the direction it needed to go. The hardware is sound, the games released for it are good. i had more of a digital library on XB than I did on PS... which is odd considering what Phil said about people and their digital libraries. I had more digital 360 games than PS3 games, and when they introduced BC for XBO... it made that decision much easier for me. And I continued to build my digital library as a result.

Yeah Series S is included in the comparison. It is overall the much more capable machine (Raytracing, higher framerate and settings at the cost of lower resolutions, NVMe SSD, etc), and $200 cheaper. And if you paid just a $100 more you got yourself a PS5 DE (still a $100 cheaper than a One X).

Sure, the One X had some deals but so did current gen consoles. Series S had crazy discounts early in the generation.

PS5 and Series X are on a completely different level, and this is before we factor in QSSR and the inevitable FSR4 which are gamechangers. But hey at least price hikes weren't a thing before the current generation. It's unbelievable how great PS5 and Series X were for their launch price. All they needed is a good upscaler.