I don't have much direct experience with BC in XBone. But, my understanding is that most games do see a performance boost. But, no games run at a higher resolution unless they were specifically upgraded to do so, and the ones that were upgraded were only upgraded for XB1X. So, on a low cost X1 you won't get that resolution.

One game from your list that I can comment on directly - RDR. I never played it on 360, so I can't give you a comparison. But, on XBone it did run very well in general. It was one of the few BC games I played, and I recall that I was impressed with how well it ran.

With that said, since MS has said that new games will be XBone compatible for a couple years, and because you want to play Halo games, why not buy and XBX? You'll be able to play all of the Halos in their upgraded glory, and play Infinite. You'll also get the benefit of being able to play the other MS exclusives that you've missed. Even if there aren't that many, when you add that to the great enhanced BC, and the excellent Halo experiences, it's probably worth the $225ish you'd pay for a used X right now.

As a huge Destiny fan myself, I can tell you that Halo games are must-play. They have nothing to do with Destiny, and they're quite different games. But, that excellent Destiny gunplay comes from Halo. If you've never played them, you're missing out. Personally, I own all platforms.  But, Halo tends to keep me as XB first, because I don't ever want to miss playing one.

Thanks that was very informative. I believe the X might be the best option since it will allow me to play all those enhanced versions plus everything released from here till next generation with more quality, plus those backlog games and what else microsoft puts out for a couple of years. Only problem is cost since I will definitely pick up the PS5 in December.

With MS saying they will be crossgen for at least 2 years then you also have a very good quality to play some exclusives in the period. Considering the release of the new machines, perhaps you can find a good deal on X1X.

Yes. Im finding some deals for used ones for around £220-250 on ebay, I believe this may be the best option then. 

Also will allow me to play Cyberpunk properly as on ps4 xbone Im almost certain we will have performance issues.

The games will run at their original resolution and framerate that they were designed for which for most games was 720p 30FPS.

However they will reach their framerate target much more often thanks to the increase in power. If a game targeted 60FPS but could only reach 40-45FPS most of the time, it will pretty much run at 60FPS on the One. Sadly dynamic resolution wasn't really a thing during 7th gen. Otherwise we probably could've seen them run at 1080p on the One (or at least on the X).

Speaking about X there are a couple of games that are enhanced for the Xbox One X.

Out of the ones you mentioned, Fallout 3, Portal 2, Red Dead Redemption and Halo 3 are X enhanced. However there's no need to get the 360 version of Halo games when you can just play Halo MCC.

Currently the BC team is working on the Series X but it's pretty much confirmed they will add more 360 (and original Xbox) games once the system has launched, so it's likely we get to see more enhanced 360 games.

RDR is 4K on X1X. I never really verified if load time are faster on X1 but I would assume they are. X1 BC even improves texture pop in so it clearly is loading data faster.

BC removes all screen tearing, which was a big problem on numerous 360 games.

GTAIV is 720p, res upgrade on BC. But its also an unlocked frame rate so the performance can be erratic. Performance is not locked on BC but normally higher and more stable.

CoD games in general are almost locked to 60 fps on BC. I did play CoD WaW a bit just to try it, felt great.

Mass Effect games is going to be best on BC for some performance improvements and less texture pop in.

All the Valve games appear to have 4K support, but I may be wrong. Fallout 3 has 4K support.

If you're gonna play old Halo games then do it via Halo MCC. 60 fps and better resolution.

BC is a great incentive to owning a X1 even if you have other consoles. Really hoping they continue to add OG Xbox and 360 games in the 9th gen.

Yup better to enjoy the version without issues.

Just one last comment, first thanks for all the help here, you guys are great.
My decision is to jump straight into the One X. Several of the games are enhanced, I will be able to play a lot of games from this generation with a much better performance and after seeing several videos it seems old 360 games on One S they do have better performance but it seems to be marginal. They still suffer from frame rate, just a little less than 360. But on One X they run pretty much locked on 30.
I watched videos for Mass Effect, GTA4 and others and you can see the One S still struggling in some areas, sometimes at 20-25 while the One X was locked at 30. So my summary of One X vs One S would be:
- Locked framerate at 30 or better if the game has unlocked framerate.
- 360 games enhanced for X
- Better loading times
- Able to run this gen games with much better performance including the ones to be released this year
- Able to run games from next generation for a couple of years while the One S will struggle here probably.

So I guess its a no brainer, a little bit more of investment but it is worth it.

Again many thanks for the help!

And for the first couple years of next gen you won't need XSX for the MS exclusives, you may just buy PS5 if you want the exclusives of Sony or just wait out until it makes sense for you to jump over.

And for the first couple years of next gen you won't need XSX for the MS exclusives, you may just buy PS5 if you want the exclusives of Sony or just wait out until it makes sense for you to jump over.