Steam Deck

The ONLY problem I have had with this, is the controller on the system itself defaults as controller 1, so SOME games it takes a little fiddling to use different controllers. But I have done this and it works great.

I've used a handful of different USB to HDMI docks, and I haven't had any problems with any of them. I just use an anker dock that supports gigabit ethernet, 100W power passthrough, and HDMI, and it works just fine.

https://www.amazon.com/gp/product/B087QZVQJX/

You can use just about any controllers using Bluetooth, I really like the wireless XBox controllers (only supported over Bluetooth) for this. But I've also used the Switch controllers and they work fine.

It's really just a slightly expensive setup for what it is, but it's also very portable, so...

Should work fine, although I found connecting 4 bluetooth controllers at once to the LCD deck didn't always work reliably. The OLED model has a better wireless chip, so this shouldn't be an issue. The OLED model also supports waking up when you turn on a controller, but this only works if the controller supports bluetooth low energy (BLE). Xbox controllers do, but if you're using a different controller you'll need to check if it supports it or not (if you want this feature).

Dock's have become much more reliable. The official dock is overly expensive imo, but it recently was updated to support CEC where the deck can turn the TV on and switch inputs to the Deck, which makes it a lot nicer for Docked play. I don't know if any of the cheaper 3rd party docks support CEC yet.

You mentioned switch emulation, but not all switch games run well. You'll need to check on the specific games you want to play.

When emulating, the Deck's built in controls will usually default to player 1. You can rearrange the controller order in both the quick-access-menu (on the deck press the ". . ." button, on other controllers hold the "home" button and press A), and in the steam input menu.

I can only speak for Wii emulation, it works great.

OLED deck have excellent Bluetooth compatibility with WiiMotes, I can hook up 4 of them using emulated bluetooth mode. (Can't get passthru mode working tho)

Some configuration beforehand such as changing all four controller slots into "real WiiMote" & enable continues scanning is all you need to do.

Just a side note. Switching between handheld and docked mode is a dull process. In order to switch input source you have to go to desktop mode every time.

If you want an emulation machine for classic games, homebrew Wii can do a lot. Not sure what good options exist for switch and ps3 though.

I regularly use mine as a couch co-op party system, though usually we are playing Steam games, not emulated games. I have played emulated WiiU, Wii, PS2, GameCube games, however, and have found that multi-controller support can be a pain with the emulators needed to play.

Hardware wise, it's rock solid for Bluetooth controllers up to four, but no more. If you need more than four controllers, you will want to wire them in with a USB hub. We've played plenty of six-person Teenage Mutant Ninja Turtles brawler using four Xbox controllers, one person with a wired steam controller, and one person holding the steam deck as the last controller.

If you go for older retro games, N64 or earlier, it gets a lot easier as retroarch is easy to play around with in game mode, where if you need to get into dolphin or something you have to go into desktop mode to make tweaks and it's just a pain, imo. This is why we typically play older stuff or steam stuff. Steam stuff is easy because it just works.

It's also super portable and I can bring the whole setup in a backpack and just requires a USB C laptop charger, my usb c dock and a HDMI cord.

It should work. But if you don't need something to carry around you could probably build a more powerful PC for the same price.

Switch emulation works pretty great. But be advised; there are problems with getting Mariokart 8 Delux splitscreen working; the game tends to soft lock on the controller applet. Rayman Legends the complete edition has no such problem and I've had a blast playing with my family.

PlayStation 2 works great and can even be pushed to render games at higher than native resolutions. I'm currently playing Spyro The Eternal Night and Ratchet Gladiator.

Since it can run PlayStation 2 that good I don't see any problems with the Deck running GameCube or Wii games... Except for the instances where Wii games may need motion controls.

PlayStation 3 requires fiddling with the settings on a per-game basis. And then still you'll probably have to downscale the native resolution and limit the framerate on games to make them run well. But the PS3 emu comes with FSR built in and I can't really complain.

Wait, how does connecting four controllers to the steam deck to play smash bros would work?

From my experience, it does not work very well. I like playing coop games with my kids, but sometimes the controllers stop working for some reason. But to change the controller config, I have to leave the game, switch to desktop mode, change settings and start the game again (in game mode).

It's possible, but a native console will likely work better.

I can't speak on multiplayer experiences, but i have several emulators set up on my OLED deck. GameCube, N64, switch, ps2. They work well, and i have a 3DO pro2 i use while it's docked to my 4k tv, sound through a surround sound bar with woofer - amazing sound. I mostly run skyrim and Balder's Gate 3 at the moment, but i enjoyed BotW and my son likes sonic.