I had the same question. Went with the OLED SD primarily to avoid windows on a handheld.

I already have a mid spec gaming laptop which should be able to play games my deck can’t.

If you’re still indecisive, you can get the ROG Ally from best buy (currently with the extended holiday return window) and see if that fits your needs. If not, you can always return the ally and get the SD.

Have you looked at the Legion Go? If you like AAA games and particularly FPS games the vertical mouse and 1600p screen and detachable controllers are super good.

I think both devices are great but you have to choose your priorities. Everyone has different things they like

If you want to use Gamepass and play more multiplayer games then the Ally is your best bet. Plus modding games is easier since it’s just standard windows. Downside is that it’s windows and out of the box it’s not super controller friendly. You have armory crate and that’s built in automatically although it’s just one option. You also have other controller friendly front ends like Steam Big Picture, Emulation Station, Launch Box, and PlayNite. Also easier to play games if you have other stores you use like GOG, Epic, EA, and Ubisoft. Anti cheat also won’t be an issue. Recommend to use hibernate over sleep because windows sleep mode is garbage.

The Steam Deck however is the king of low power gaming as well as having better battery life. Expect much longer run times than the Ally at low watts as the deck can lower its TDP lower than the Ally. If you mostly play single player games from Steam then this will be your better choice. It’s also a bit more console like meaning some people find it much easier to use. Plus it’s sleep mode works much better than windows modern standby.

Screen wise I think both could be argued to be better than the other however in my eyes I see both as equal and are fantastic

TL;DR IMO buy the OLED.

Generally speaking all of the windows handhelds have MANY reliability issues, for some they work just fine and for many they barely work at all or have recurring issues that bog down the experience. Or you might even get really unlucky with defective models (a common issue with the ROG Ally).

So if you want something as refined as PC handhelds get, the steam deck is your best option. But if you want an alternative the Legion GO is currently the best of these deck competitors; it’s the only competition to have a better screen than the OLED deck in terms of colour accuracy anyway. It also has the same battery capacity, tho it will have much worse battery life than the steam deck (especially the OLED).

For me I would go with the OLED because of the many quality of life features that it has that simply don’t exist on alternatives yet, not to mention steam is being designed best for the steam deck. The OLED is also really inexpensive on the 512GB model, not to mention third party SSD’s can go up to 2tb, or for 1tb they can be cheaper than buying a 1tb model. I am a long term deck user so I am very biased, and I’m especially biased since I’ve never used any other PC handhelds. So take my words with a heap of salt.

The Ally has enough QC issues that my local best buy has enough open box returns to equip a platoon.

The Ally also has hardware issues like a still unaddressed tendency to damage SD cards, which the Ally community has responded to with Stockholm-syndrome esque “it’s okay, I’ll just install a 2tb SSD so I don’t need an SD card!” behaviors.

And the worst part? The very worst? For all its vaunted performance, it isn’t actually much better in the AAA games the Deck actually struggles with. Returnal is still unplayable. Starfield is still okay everywhere but cities, where it chugs. RDR2 will get you to 45-50 fps instead of 30-40, but you’re still on all low settings at 720p res, except now you’re using upscaling to fit the Ally’s 1080p screen.

Disclaimer: My view of the Ally is tainted by how I stupidly allowed myself to be roped into tech support for my friend’s lemon of an Ally because “Hey, Facehugger, you have a Steam Deck and you’re good with tech, right?” The Ally I have actual hands on experience with was probably a demonic engine from the pits of hell made to torment me.

If you want a relatively easy experience the Deck is a better product for pick up and play.

the ROG in my experience is a nightmare when things don’t want to work.

Based on your description, I think you’d be best off with the Ally, as it is the straightforward choice for a strong focus on AAA games. VRR and a bit more graphics power, no problem with launchers or anti cheat systems, and no need for control options since they are generally made for gamepad.

Windows is still a big pain on handhelds, so I’d stick with the OLED. If you’ve got a PC, remote playing via Moonlight + Sunshine is just like running native but saving a lot on battery life. Pair that with the only OLED HDR screen on the market, no other handheld can come close to that experience

I have both systems. So close in price, for you, I’d go with more powerful system. I have original SD, ally z1 extreme, and purchased oled SD. If price so close, go with more future proof system, ally. But Sd is still great with a lot of unique features. I wanted more power to play AAA games, so ally was my choice. But that SD oled was too much for me to resist. I will give my OG sd to my daughter and introduce her that way to pc gaming on Linux as she stuck on playing iPad and switch games. Good luck on choosing!

Unless you have specific games you want to play that won’t work on Linux due to the anti cheat (destiny 2, call of duty, and a couple others) I would just go with the steam deck. Adding other store fronts is not as hard as people think it is. Adding epic and gog are super easy, and the rest are not much harder.

You’ll get a more console like experience with steam deck, with more aftermarket accessories, and a better looking screen.

I’ll always recommend the Steam Deck over any other handheld gaming device because it gets more support from Valve and from other devs. It may not be the most powerful, but it’s more reliable and future proof.