The backlight!!! Why was this not a feature on all of the gameboys haha. I love it, I have it on the lower settings normally. Yesterday, I was on a flight coming back from NY and we hit England in the morning. When I opened the blind to BLINDING sunlight. I just upped the brightness a notch and job done!
The GBA SP that I bought is a fully refurbished one, new plastics, buttons and screen. It looks brand new. Apart from the shoulder buttons which have been used a lot as the click on them is pretty weak. Something I can easily fix in jiffy so not that fussed.
Other than that, I have not put it down! I have logged how much time I have played it over several games. I fully charged it in New Jersey on Friday last week. Since then I have done 9 hours... Don't know if you get a warning light or anything. But no failings yet!
This morning was AWESOME, I got on the train. Pulled out the Gameboy and got stuck into Golden Sun. Love it

I love the idea of all of these little gems that I have missed only just coming into my gaming career haha.