ok, so it's also about how you prefer to hold the control. I find the xbox control very comfy, and the battery doesn't get in my way, however with the DS3, it feels like I have to turn my wrists in more, which isn't so lekker for me.
Then there's the R1,R2,L1,L2 buttons. With the xbox control, the triggers are more nice and triggery. Nice for shooters, and make for good pedal substitutes with driving games. The "bumper" buttons are easily pressable even when using just your index fingers there, you can press them with a knuckle, but with the DS3, you really need to have your index and middle fingers hovering there, which just feels awkward to me.
I don't mind the weight because I usually lie on the couch with my feet up, and I can rest my arms in my lap, and the weight makes it feel more substantial.
But that's just my personal preference I guess.