Pheace: Is it crashproof?
According to first tests it's very good, both the higher resolution display and the power outmatch the Steam Deck, depending on the model you can have about 5 times more power than the Steam Deck. Also the cooling system is great, works much better.
But currently the software still has flaws, sometimes SD cards don't get recognized after a while or a game gets detected multiple times by the UI.
Of course Windows is not designed for such small screens. Microsoft working on a UI designed for handhelds, but it will take some time. Until then third party software is better than links on the desktop. A possible solution might be to set the desktop to a lower resolution and use Full HD only for games. Also the battery life is not as high, that's the tradeoff if you have more power.
Make sure to also check out the GPD Win 4, which is currently available and on a similar quality level.
A workaround for small screen sizes and high resolution might be to use a remote session software like AnyDesk or TeamViewer (free edition). You use your PC to set up your handheld remotely and only use it for playing.
I'm waiting for the Aya Neo Slide, which has about the same tech specs as the Asus ROG, but the sticks seem to be higher quality than those of Steam Deck and Asus ROG. Like the GPD Win 4 it has a full keyboard under the screen. Additionally the screen can be tilted up (45° I think), so you can lay the handheld on the table and play mouse games or type.