OneXPlayer are a series of handheld gaming devices, they're somewhat popular and it appears they've been keeping a close eye on SteamOS and how it's been working on the Steam Deck.
Currently they offer various models like the OneXPlayer Mini, OneXPlayer 1S, two AMD models and the One-GX 1 Laptop. However, all of them currently ship with Windows. Some of them are pretty powerful too, like the currently sold-out "ONEXPLAYER AMD® - 8.4 inch Ryzen® 5700U" model. Their prices are quite a bit higher than Steam Deck too, with that model in particular retailing at $1,419.
The good news is that they might actually be shipping SteamOS Linux in future, bringing them more in line with what the Steam Deck can do. As WePC recently did an interview with the VP of OneXPlayer, Jason Zeng. Here's the excerpt:
Zeng continued to share his opinions on Valve’s market-disrupting machine by giving his stance on how Valve managed to achieve success with the device. ‘Steam Deck is a very influential product that has managed to leverage its accumulated assets and bring [the] public’s attention to the field of portable gaming. We sincerely congratulate Steam Deck for its achievements, and will keep working on our competitive edges.’
Of particular note is how the Proton developers actually improved performance in games such as Elden Ring, which highlights the OS against running something a little harder on the system like Windows 11. Zeng comments that the team has been ‘working on’ shipping the OneXPlayer line of devices with a build of Linux or SteamOS in the future.
Having more devices out there shipping Linux sound awesome. However, they seem to have no plans for cheaper devices right now, so you might want to keep waiting on and sticking with the Steam Deck if you don't have a ton of spare cash stuffed under your bed.