Teh speed really does not matter. A 7+ MHz Amiga could push as much on screen as a 25 MHz 386... And teh fact that you are comparing a CISC to a RISC procesor, adds to the equation in favour of the GBA
I don't think it is underpowered, what do you want in there, 3D games? NO THANKS
Teh Lynx, afaik, can push 16 on-screen. It has a palette of 4096, just like the Amiga, but can't put' em all in there at once, just like the AMiga (not counting HAM mode of course). It features stuff as copperbanding, etc., that makes it look just like an Amiga. Believe me, check out SotB for a shock
Teh PSOne LCD screen is complete garbage. A step (quite a few really) back in technology.
PS: Just found out, the GBA's 32 bit RISC processor, really runs at 33 Mhz, not 16
and OI! Who deleted your post???? Damn strange!