How does Penny even afford that place (and buying shoes all day and clothes cuz she doesn't do laundry) working part-time as a waitress and it takes TWO physicists to afford their place? I even remember Sheldon saying something like, to Leonard, "Frankly if I could afford the rent I'd kick you out." I know, two bedrooms vs one, but you gotta think Leonard makes at least 5x what Penny would working full-time.
But, yeah, Amy is more robotic than Sheldon, and I never thought I'd be saying that about anyone. Really, though, if she was a drop-dead hottie then it would create some interesting competition with all the other guys and this might even have made Sheldon jealous. Yeah, she's Blossom, and really smart, but they shouldn't have solely based her casting on that criteria alone.