falcon, cuz it would be cool.
This was essentially my rationale. Light Emission is tempting, and I can envision lots of ways that it could be used awesomely. But turning into a falcon and flying?! No contest. Plus the gouging people's eyes out thing. Touch of Death is powerful, for sure, but the sacrifices were too great.
If I had this to do over again, I might give them all drawbacks. Like for Light Emission I was thinking maybe you would always glow a little. In daylight it's not noticeable, but in the dark it makes you look radioactive. You can turn it off by an act of will, but it's difficult to hold it for more than about five minutes; at ten minutes the strain is unbearable and you let go and light up.
I'm not sure what the drawback would have been for Falcon Form. You lay eggs?