The SP was pretty painful to hold and use for long times in my experience. The shoulder buttons were particularly hard to hit comfortably. The original GBA horizontal design is my favorite and most comfortable. Swap it to a nice backlit LCD or even OLED and it would be perfect.

GBA wasn't bad but it was bulkier to carry on your person. The portability of the SP was killer and the beautiful LCD screen was protected in your bag or pocket.

As far as ergonomics, it wasn't so bad. For more action oriented games, it could be a bit tiring, but for Pokemon it was the perfect machine.

Ds Lite imo is even better. Its thinner so it fits easier in the pocket even though its wider. You put in a flashcart with a 32gb micro sd and now you can store every game worth playing from the nds, gba, gbc, gb, snes, nes, sega genesis, various ataris and other early game systems. It has the longest battery life for a nintendo handheld I believe. Plus I find it pretty comfortable in adult hands still, definitely moreso than the nintendo switch.

The one pain point on the DS Lite is that if you want to put in an actual, physical GBA cartridge it sticks out. Everything else is great.

Good point but I'd contend that the SP might have been more durable. I'm not sure. Either way, I liked the weight of it over the DS lite. Both great devices though.

I think the relative peak was the micro's black and silver (either way) design, personally.