Brief summary - more recent APU so if you're plugged in to power, the Ally can play games at higher settings. If you're not plugged in, reviewers found that the minimum power draw is high so your battery life is worse (both have the same battery capacity). The best case scenario for the Ally is 4 hours while it's closer to 7 for the Deck.
On the software side, the Deck benefits from a large community of folks creating control mappings for older games. Windows handicaps the Ally - it's just clunky to use in this form factor.
On the other hand...playing 7h straights sounds crazy to me. OK you can do more than playing with these devices, like using them as regular travelling computers with bt keyboard+trackpad combo but still, there is a lot of chance that after 2-3 hours you should be able to find a power outlet and take a pause in your gaming.
That's 7h in ideal circumstances, running light games with a low screen brightness. If you open a full AAA game and let the deck really start slurping power it will get like 1.5 hours at best in my experience. I can get 4 hours when playing emulated PS2 games, but around 1.5 playing something modern like The Outer Wilds on my steam deck.
The ally is much less efficient with the same battery capacity. I've seen reports of like 40 minutes of battery life when running high power draw games.
> If you open a full AAA game and let the deck really start slurping power it will get like 1.5 hours at best
But would you want to spend that time playing with an undocked 700gram device in your hand, in a bad posture looking down at a screen? Even my much lighter Switch I would not play more than 45 minutes straight in portable mode.
Very true, but that comparison gives you two play sessions between charges on the steam deck instead of one for the ally. Considering one of the biggest criticisms of the steam deck is battery life, and as a steam deck owner, I find the ally very uncompelling. It goes out of its way in almost every aspect to draw more power: runs windows, higher-power chip, higher-resolution screen. Then does nothing to solve battery life. What's the point of a handheld if you're tethered to a wall, a smaller bag to carry the charging brick?
The ally just seems to be chasing 'look how high the specs can go' instead of practically improving on the steam deck.
You usually have access to power in long flights between continents and national train lines.
But you don't want to play that long on a portable device anyway, position is just terrible for your posture/neck and I don't think it is really healthy. What you want is alterning occupations: video games, reading, sleeping, drawing, card games, listening to music, making music, chatting, eating, moving in the main aisle, etc.
Brief summary - more recent APU so if you're plugged in to power, the Ally can play games at higher settings. If you're not plugged in, reviewers found that the minimum power draw is high so your battery life is worse (both have the same battery capacity). The best case scenario for the Ally is 4 hours while it's closer to 7 for the Deck.
On the software side, the Deck benefits from a large community of folks creating control mappings for older games. Windows handicaps the Ally - it's just clunky to use in this form factor.