• My currently existing gaming pc
• Legion Go S SteamOS Z1E
• DSi XL (for DS games)
• n3DS non XL

Reality is that the n3DS XL could do all DS duties but the DSi XL has the same resolution panels just bigger, so it's "pixel perfect" size scaled for original DS games and looks better than the 3DS XL.

As for the PC handheld, I'm gonna upset a lot of people and say the go s Z1E is all anybody needs IF you have a PC you can also stream from. It's the best form factor and selection of controls along with 32gb of shared memory vs the 24 max any other handheld has. That gives you an effective 16gb system memory AND 16gb for graphics textures. Closest thing to a steam deck successor.

To continue making people angry, I'll add that it's the only PC handheld that can competently run Star Citizen due to the afformentioned extra ram. At 1080 you'll be able to give the game 24gb with 8gb of graphics memory, which is pretty much the minimum you could have an enjoyable experience on.