The third party options all have more powerful APUs, so you get one of those if you want higher tier performance.

Pros: Higher res, better APU

Cons: Trackpads gone

Honestly - lack of large trackpads aside (it does have a tiny one on the right side) - the Legion Go S looks like a good deal. Price should be equal to the OLED Deck for the 512 GB variant, for that you get a device with a more modern CPU architecture and 50% more GPU cores. The display is quite a bit larger (8.1" vs 7.4", which is a larger difference than it might seem), it's higher resolution 120 Hz and - most importantly - it has VRR, which the Steam Deck OLED lacks. Sure, it's not OLED and some people are seemingly allergic to higher resolution displays ("think about the battery life!!!" or "not powerful enough to play games at this res" (upscaling exists)), but 2D games like Hollow Knight or Cuphead should look amazing on this display and font rendering should be a lot better.

Also, Lenovo might sell this in countries where the Steam Deck isn't officially available.

USB 4

The primary reason why I don't currently own a Steam Deck.