However, I didn’t really care that much considering how much better the Game Boy Advance SP was than all the previous Game Boys.
It was the first Game Boy to have a backlit screen, which meant I could finally easily sneak and play on it in the night without alerting my parents (instead of trying to do the same with the much less effective wormlight accessory I had for my Game Boy Advance).
The D-pad was far more comfortable to use over long periods compared with the ones on previous Game Boys. I distinctly remember having my left thumb hurt after playing for a few hours on my Game Boy Advance, since the D-pad on that one makes you feel like you have to press down a lot harder than the one on the Game Boy Advance SP.
And the biggest point: it was the first Game Boy to include a rechargeable battery! This was huge, since people really didn’t buy rechargeable batteries nearly as much back then as they do now, so you’d pretty much be either wasting two alkaline batteries per day or two, or staying tethered to a wall by using the included AC adapter. That was a pretty annoying option too, especially when the power in your home died right before you could get to a save point…
When I got one, I essentially stopped playing GBA games on my Game Boy Advance, since playing them on my Game Boy Advance SP was a far more enjoyable experience (so much so that I didn’t really lament the loss of the headphone jack all that much).